Lippert Components, the Indiana-based subsidiary of LCI Industries, completed its acquisition of Lewmar Marine Limited on 1 August 2019 for £33.286 million; Lewmar's sales in 2018 were about £55 million. Lewmar was founded in 1946 in Havant, Hampshire, England. Its US office was Guilford, Connecticut in the 2018 manuals and the 2019 release; the 2020 manual prints Gloversville, New York, and lewmar.com prints no US address today. LCI Industries announced an all-stock merger with Patrick Industries on 30 June 2026, expected to close in the first half of 2027.

How long is the Lewmar thruster warranty?

The manual says 3 years for normal private pleasure-boat use, then limits cover to 1 year for "Electric motors and associated electrical equipment" and "Electronic controls", among others. It excludes removal, transport and installation costs, and is void if anyone other than an authorized Lewmar representative services the unit.

How long can a Lewmar thruster run?

The Gen 2 manual says that if the thruster runs constantly in one direction for more than 3 minutes the system enters fault mode, and that a thermal switch stops the motor if it overheats; its fault-finding table says to wait 20 minutes for the motor to cool. The pre-Gen 2 manual said the unit "should run for approx. 3 minutes continuously". The system powers itself down after 15 minutes without use.

How much does a Lewmar bow thruster cost?

In our database, Defender's prices captured 13 October 2026 run from $935.99 for the 110TT Thruster Kit to $3,426.99 for the 6 kW 185TT Gen 2; the 250TT and 300TT, which Defender does not list, are $4,949.00 to $10,499.00 at Marinedeal, and the retractables are $8,686.99 and up. On 2 October 2026 Lippert's own store listed the same part numbers at 81% to 95% more. Our own yard estimate for the 185TT on a 48 ft sailboat is $9,108 to $22,238 all in, the 3 kW motor with the cheapest yard hours at the low end and the 6 kW with the most expensive at the high.

Lewmar Thrusters: What They Publish and What Owners Report

The short answer

What it is

Eight series and 16 units, from 62 to 616 lb. The TT units go through the bow below the waterline in a . The RT and VRTT series are . Every one is fitted with the boat out of the water.

Who it suits

You, if you want to order this week from a chandlery with the manual in hand, or already have one aboard.

The main strength

You can buy it this week and read the rules first. The manual prints the whole model ladder, a current and cable table, and the clearest run-time rule of any maker on this site.

The main limit

The warranty says 3 years, but the motor and the electronic controls get 1 year. Almost every owner report we read is about those parts, above all the older controller.

What it costs

Defender lists tunnel units from $935.99 for the 110TT Thruster Kit to $3,426.99 for the 6 kW 185TT Gen 2, unit only. Marinedeal has the 250TT and 300TT at $4,949.00 to $10,499.00. The retractables are $8,686.99 and up. Our yard estimate for the 185TT on a 48 ft sailboat is $9,108 to $22,238 all in, from the 3 kW motor with the cheapest yard hours to the 6 kW with the most expensive. Defender was the cheapest of the three stores on every row we could match.

What they publish

Our database holds eight Lewmar series: 16 units in 12 rows, because the 185TT Gen 2 motors share one row with a low and a high figure, and so do the two 300TT motors.

The list below is our database by type and series, with a line on what each series adds and the run-time rule its documents give; a kit or package sits under the unit it is sold with. Open a type to see its models. Folded under it is the maker's own Gen 2 ladder from the manual, cut to the rows this page discusses, with each unit's current draw beside it.

Tunnel thrusters A tube through the hull 10 models

Lewmar’s tunnel thrusters, by series, a build of the same size indented under its standard unit. Thrust is the maker’s, in pounds with kilograms under it. Motor is the maker's rating; current and run time are from its manuals. A dash means no figure on file. “Same” means the standard unit’s figure applies. Prices are the dealer’s, dated on each model’s page.
Model	Thrust	Motor	Current	Tunnel	Boat length	Run time, min	Price
110TT 2 models The smallest: a 110 mm tunnel, a composite gearbox and one five-blade propeller. Run time, as published: Not on the listing. The manual gives 3 minutes in one direction, then fault mode.
110TT Kit	62 lb 28 kgf	1.5 kW	215 A · 12 V	110 mm	Not published	3, one way	$936
110TT 1.5 Complete PackageThe complete package	same	same	same	same	same	same	$1,339
125TT Gen 2 1 model A 125 mm tunnel between the 110 and 140, one five-blade composite propeller, 2.0 kW on 12 V. Run time, as published: Not on the listing. The manual gives 3 minutes in one direction, then fault mode.
125TT	77 lb 35 kgf	2 kW	—	125 mm	Not published	3, one way	$1,846
140TT 3 models The same gearbox and single five-blade propeller in a 140 mm tunnel. Run time, as published: Not on the listing. The manual gives 3 minutes in one direction, then fault mode.
140TT	82 lb 37 kgf	2 kW	270 A · 12 V	140 mm	30 to 35 ft^†	3, one way	$1,486
140TT KitThe kit	same	same	same	same	same	same	$1,965
140TT Gen 2 PackageThe complete package	92 lb 42 kgf	2.2 kW	280 A · 12 V	same	31 to 40 ft^†	same	$2,754
185TT Gen 2 2 models Four motor sizes for one 185 mm tunnel; the 6 kW also comes on 24 V. Run time, as published: Not on the listing. The manual gives 3 minutes in one direction, then fault mode.
185TT GEN 2	128–214 lb 58–97 kgf	3 to 6 kW	330–700 A · 12 V160–370 A · 24 V	185 mm	51 to 60 ft^†	3, one way	$1,912–$4,825
185TT GEN 2 PackageThe complete package	128 lb 58 kgf	3 kW	330 A · 12 V	same	36 to 45 ft^†	same	$2,239
250TT Gen 2 1 model Twin counter-rotating propellers in a 250 mm tunnel, on 24 V. Run time, as published: Not on the listing. The manual gives 3 minutes in one direction, then fault mode.
250TT GEN 2	308 lb 140 kgf	8 kW	500 A · 24 V	250 mm	Not published	3, one way	$4,949
300TT Gen 2 1 model The largest: twin counter-rotating propellers in a 300 mm tunnel, on 24 or 48 V. Run time, as published: Not on the listing. The manual gives 3 minutes in one direction, then fault mode.
300TT GEN 2	550–616 lb 249–279 kgf	10.8 to 15 kW	650 A · 24 V420 A · 48 V	300 mm	76 to 80 ft^†	3, one way	$7,339–$10,499

Retractable thrusters Lowers from a housing, lifts clear when stowed 2 models

Lewmar’s retractable thrusters, by series, a build of the same size indented under its standard unit. Thrust is the maker’s, in pounds with kilograms under it. Motor is the maker's rating; current and run time are from its manuals. A dash means no figure on file. “Same” means the standard unit’s figure applies. Prices are the dealer’s, dated on each model’s page.
Model	Thrust	Motor	Current	Bore	Boat length	Run time, min	Price
RT185 MX Gen 2 1 model Lowers when the panel is switched on; the piece cut from the hull becomes its door. Run time, as published: Not on the listing. The manual's rules apply, and it powers down after 5 minutes idle.
RT185 MX Gen 2	214 lb 97 kgf	6 kW	700 A · 12 V370 A · 24 V	185 mm	51 to 60 ft^†	3	$8,687–$9,034
VRTT 1 model Drops straight down on a lead screw and rises back out of the water. 24 V. Run time, as published: Not on the listing. The manual's rules apply, and it powers down after 5 minutes idle.
250VRTT Vertical Retractable	353 lb 160 kgf	—	520 A · 24 V	250 mm	56 to 65 ft^†	3	$29,417

12 models in all. ^† The listing prints no boat length; this one is from Lewmar's selection chart, by windage.

Show Lewmar’s own table from the Gen 2 manual

The Gen 2 ladder from the installation manual (559231 Iss.3), read 13 September 2026, cut to the rows this page discusses. Thrust is as printed, in and pounds. The draw and smallest cable come from the manual's current table, for the same model and voltage. The manual's full table adds the 250 and 300 series, the IP versions of these units (the same figures a kilogram heavier) and the other hydraulic units. Boat length: none, on any row.
Model	Thrust	Motor	Gearbox	Fuse	Current draw	Smallest cable
110 12v	28 kgf (62 lb)	1.5 kW, 2 hp, 12 V	Composite, Single	200 A	215 A	50 mm², 12 m
140 2.0Kw 12v	37 kgf (82 lb)	2 kW, 2.7 hp, 12 V	Composite, Single	200 A	270 A	70 mm², 14 m
140 2.2Kw 12v	42 kgf (93 lb)	2.2 kW, 3 hp, 12 V	Composite, Single	200 A	280 A	70 mm², 12 m
185 3.0kw 12v	58 kgf (128 lb)	3 kW, 4 hp, 12 V	st/st, Single	250 A	330 A	95 mm², 15 m
185 3.0kw 24v	58 kgf (128 lb)	3 kW, 4 hp, 24 V	st/st, Single	130 A	160 A	35 mm², 12 m
185 4.0Kw 12v	65 kgf (143 lb)	4 kW, 5.4 hp, 12 V	st/st, Single	400 A	470 A	150 mm², 16 m
185 4.0Kw 24v	65 kgf (143 lb)	4 kW, 5.4 hp, 24 V	st/st, Single	130 A	235 A	70 mm², 16 m
185 5.0Kw 12v	82 kgf (181 lb)	5 kW, 6.7 hp, 12 V	st/st, Single	400 A	480 A	185 mm², 21 m
185 5.0Kw 24v	82 kgf (181 lb)	5 kW, 6.7 hp, 24 V	st/st, Single	130 A	240 A	70 mm², 15 m
185 6.0Kw 12v	97 kgf (214 lb)	6 kW, 8 hp, 12 V	st/st, Single	500 A	700 A	300 mm², 22 m
185 6.0Kw 24v	97 kgf (214 lb)	6 kW, 8 hp, 24 V	st/st, Single	325 A	370 A	120 mm², 18 m
TT 250 Hyd Gen 2	200 kgf (240 lb as printed)	15 kW, 20 hp, hydraulic	Twin CR	—	—	—

What they publish about the system

The rules that apply to the whole range, with a note where two of the maker's own documents disagree or one document is wrong.
Topic	What the maker prints	Our note
Warranty	"3 years from the date of purchase by the end user"	Exceptions: 1 year on "Electric motors and associated electrical equipment" and "Electronic controls"
Run time	Gen 2 manual: "If the thruster is operated constantly in one direction for more than 3 minutes, the system will enter fault mode." A thermal switch stops an overheated motor, then "Wait 20 minutes".	Pre-Gen 2: "approx. 3 minutes continuously". No product page prints either.
Idle timer	Gen 2: off after 15 minutes (tunnel), 5 (retractable)	Pre-Gen 2: 5 minutes
Reversal delay	Pre-Gen 2: "a 1.5sec delay built into the system"	Gen 2: "a short delay", no figure
Boat length	None in the manual or on the product pages	Fisheries prints "Typical Boat" per listing, two bands for the 6.0 kW
Thrust	One figure per model, kgf and pounds, no voltage stated for it	Hydraulic TT 250 Hyd Gen 2: "200 240"
Current and cable	The stated draw, minimum section and longest run, per model. On the battery: "Battery crank capacity should be at least equal to the thruster current."	The 250 8 KW row's voltage cell reads "224"
Voltage at the motor	At the motor, "minimum 10V for 12V and 21V for 24 V units". The amber LED "is for indication only".	Consistent
Tunnel	"As far forward as possible (lever effect)". Depth: 1 diameter under, 0.75 minimum. Length at least 2 diameters. Wall thickness per model.	Consistent
Servicing	Anode checked at 3 to 4 months on a new install, replaced yearly. "Brush out carbon dust"	Owners: brushes not sold separately, the motor is

Sources: the Gen 2 installation manual (559231 Iss.3, Defender's copy), the Gen 2 control manual (559232 Iss.1, a dealer's copy) and the pre-Gen 2 manual (Issue 2, West Marine's copy). The web pages are the About page, the Gen 2 TT product page and thruster listing, the Lippert press release, Lippert's store, and Fisheries Supply's Lewmar listings and 185TT 6.0 page.

Two more slips on the maker's web pages, outside the system rules. The About page names the founder two ways: "Len Lewrey" in 1946, then "Len Lewery and Leslie Marsh in 1950" in its last paragraph. The Gen 2 product page prints "We have no additional data for your currently selection." until an option is picked, and nothing in its markup.

The warranty: three years, one year on the motor

In brief. The manual promises 3 years. Its exceptions then put the motor, the and the controller on 1 year.

Every Lewmar manual we read ends with the same page, "Limited Warranty and Key Terms of Supply". Its first sentence: "Lewmar warrants that in normal private pleasure boat usage and with proper maintenance its products will conform with their specification for a period of three years from the date of purchase by the end user".

Then comes section B, headed "EXCEPTIONS". It reads: "Cover under this Warranty is limited to a period of one year from the date of purchase by the end user in the case of any of the following products or parts of products". The list opens with "Electric motors and associated electrical equipment" and "Electronic controls". Next come "Hydraulic pumps, valves and actuators", weather seals, racing, charter and anchor rodes.

Here is what that means on an electric thruster.

One year: the motor, the and the controller. By our reading, they are the "electrical equipment" and the "electronic controls" the exceptions name. Almost every owner report below is about this group.

Three years, by the same reading: the , the hub and the propeller.

The rest of the page narrows the cover further. It leaves out the cost of getting the unit out and back in: "This warranty does not cover any incidental costs incurred for the investigation, removal, carriage, transport or installation of product."

It also sets who may work on the unit: "Service by anyone other than authorized Lewmar representatives shall void this warranty unless it accords with Lewmar guidelines and standards of workmanship." The claim goes "to the Lewmar outlet that supplied the product".

A Ranger Tug owner summed it up in Oct 2020: "3 year 'parts-only warranty'". The one warranty repair on record, a 185TT gearbox "full of water and no oil" in Feb 2025, was "part only".

How long it runs: three minutes, then fault mode

Three minutes of steady push in one direction is far more than a docking takes. The Gen 2 manual's "Operation and safety features" page is the clearest run-time page any maker on this site prints, and it sits in the thruster's own manual.

Fault mode. "If the thruster is operated constantly in one direction for more than 3 minutes, the system will enter fault mode." The LED turns red.

Thermal switch. "The thruster motor is fitted with a thermal switch to prevent thruster activation if the motor overheats". The LED flashes red and clears itself "Once the motor returns to a safe temperature".

Idle power-down. The system switches itself off after 15 minutes idle on a unit and 5 on a , a safety timer.

The fault-finding table says how long the cooling takes: "Long operation has tripped thermal switch. Wait 20 minutes for motor to cool and reset". It adds a warning: "DO NOT attempt to cool motor by any other means."

The pre-Gen 2 manual said it more loosely: "The performance and duration of the thruster will vary with conditions but should run for approx. 3 minutes continuously." Its panel switched off after 5 minutes. Its reversal delay was "1.5sec". The Gen 2 manual says "a short delay" and gives no figure.

Two owners on big boats say the limit never came. One has a 185TT 8 hp that is "too small for my boat" and "has to run a lot, but I have yet to timeout". The other's 24 V unit "has never timed out, in a few cases with steady operation in excess of a minute".

No Lewmar product page and no dealer listing prints the three minutes. Defender's rows say "thermal".

The old controller that ran on its own

Older Lewmar controllers have a record of starting the thruster by themselves. The Gen 2 electronics are the maker's answer, and a converter lets an older boat take them.

The longest thread about this brand is called "Haunted Lewmar 185 thruster". It runs from May 2017 to Mar 2020. It opens with a marina's phone call: "my bow thruster has turned on and had been running for an extended time."

The second owner has the same model, seven seasons old. He found that "the problem was with the potted electronics in the joystick assembly". It started with a ham radio transmitter ("When she hit the morse key, boat spun around the mooring buoy!"). Then came "random runs of the bow thruster to starboard" that "got worse over the course of a week". He rewired the joystick "to be a dumb switch set".

In Feb 2020 a 140TT fitted as a stern thruster "started on it's own in the middle of the night... ran for over half an hour before a live aboard neighbor woke up from the racket". By morning "all the plastic has melted down. It's toast."

The maker's side reached the thread through a dealer. A Cutwater 30 of 2017 spent "the entire 2018 cruising season being plagued (or as I came to describing it 'possessed') by the bow thruster going off randomly, both with the boat underway and when docked".

The dealer's mechanic "worked on it a half a dozen times". The mechanic "finally got Lewmar to acknowledge that there was a problem with the design of the controller. They promised to send replacements. It took over a month for anything to show up, an then they sent the old model." The right ones "had a 'little black box' attached. That finally solved the problem."

That box is the Gen 2 system. The control manual lists a "Blue Box Converter" so an older thruster takes the new panel. The 2020 owner was told this: "they now have what they call Gen 2 compliant joystick, control cable and a blue box converter that wasn't available when I bought my thruster in 2018. BTW... no one from Lewmar ever contacted me about this issue and I'm registered".

The Gen 2 manual now adds a check at switch-on. The system goes into fault mode if a port or starboard signal is already present. The manual says this "prevents the thruster from unintentionally activating during start-up due to a wiring fault, or a second joystick accidentally being operated."

Switch it off when you leave. Every owner in the thread ends with the same rule, and so does the manual: battery switch off whenever the boat is left.

What length of boat it suits

Lewmar's manuals give no boat length. One product page does: the Small Boat TT page says "up to about 28ft" for the 110TT.

Fisheries Supply prints one anyway, a "Typical Boat" line on each listing.

The 140TT 2.0: up to 35 ft.

The 185TT 3.0: 35 to 45 ft.

The 185TT 6.0 at 12 V: 46 to 66 ft.

The 185TT 6.0 at 24 V: 45 to 55 ft.

Those last two are the same 97 motor and propeller in the manual's table. The listing's description line says the range "covers all boats from 30 to 150 feet". We do not know where the bands come from, and the dealer's page does not say.

Here are the two 6.0 kW bands set against our size calculator, the tool here that works out the thrust a boat needs, at their tops. At 66 ft, in a 15 knot breeze, the calculator asks a unit for about 293 lb on a motor yacht, and the same on a trawler, which it sizes alike. The unit's 214 lb steers either boat at about 13 knots.

At 55 ft, the top of the 24 V listing, the motor yacht needs about 203 lb. The unit's 214 lb steers her at about 15 knots.

The smallest 185 is 128 lb. At the top of its 35 to 45 ft band the calculator wants about 133 lb on a sailboat and about 135 lb on a motor yacht, so it steers either boat at about 15 knots.

That is our calculator applied to a dealer's bands. Run the calculator for your own boat and it shows the arithmetic.

What it drills

A . Every TT unit goes through the bow below the waterline in a tube of 110, 140, 185, 250, 300 mm. The manual's placement rules match the this site sizes by.

Where: "As far forward as possible (Fig 3.1.1 / lever effect)."

How deep: "1 x Ø below the waterline to prevent air being sucked into the tunnel (0.75 x Ø minimum)."

How long: "Minimum suggested tunnel length 2 x Ø."

How thick: a wall-thickness table per model. The 185 at 5 and 6 kW wants a thicker tube than at 3 and 4.

The 110 and 140 use a composite gearbox and a single five-blade propeller. The 185 uses a stainless one. The 250 and 300 have twin counter-rotating propellers on aluminum or bronze. The 140 and 185 drive through a the manual shows how to change. The 250 and 300 do not.

The are a different product at a different price. The RT185 MX Gen 2 has the same 214 lb as the biggest 185TT on Defender's page, at $8,686.99 to $9,033.99. The 250VRTT vertical retractable, Defender's 160 kgf max thrust, is $29,416.99. The tunnel manual does not cover them, and each has a manual of its own. The 250VRTT’s is Lewmar’s 250 and 300 VRTT manual of 2007; the only copy online is a dealer’s. It says to fit the unit as far forward as possible, so it is a bow thruster.

Plan for a . Every one of them is fitted with the boat out of the water.

Our types page and the cost page carry what a tunnel costs at a yard. The DIY page has the two owners who fitted a 140TT themselves.

Current, cable and one sentence on the battery

The manual gives three figures per model and voltage. They are the stated current draw, the smallest cable section in square millimeters, and the longest total run (battery to thruster and back) that section will carry.

The 110 1.5KW draws 215 A on 50 mm² to 12 m.

The 12 V 185 3 KW draws 330 A on 95 mm² to 15 m.

The 12 V 185 6 KW draws 700 A on 300 mm² to 22 m, or 370 A on 120 mm² at 24 V.

These figures are from the Gen 2 manual Iss.3 (2018), the edition Defender hosts. Lewmar's later edition, Iss.5 (2020), keeps everything else and withdraws this table. In its place it prints two generic tables of current against cable distance and calls them "guidance only". It also adds a 125TT (591251, 2.0 kW, 35 kgf).

The worked example is a 250 8 KW on a 28 m run needing 95 mm². The table's own row for that unit says 185 mm² to 20 m; the example is a cell from the older manual. The same row prints the unit's voltage as "224". The voltage at the motor "should be 10V for 12V and 21V for 24 V units" while running. The panel's amber low-voltage light "is for indication only and will not affect thruster performance".

The battery gets one sentence: "Battery crank capacity should be at least equal to the thruster current." There is no table, no and no chemistry. The 12 V 6 kW unit's 700 A is the whole specification.

One oddity in the table, by our division: the 12 V 4 kW draws 470 A for 65 and the 12 V 5 kW 480 A for 82 kgf. That is 0.138 and 0.171 kgf per stated amp. The two motors are a kilowatt apart, yet their stated draws differ by only 10 A.

Our battery page covers the makers that publish a cranking figure. The wiring page has the cable rules.

What owners report

The reports come from builders' customers (Ranger Tug, Cutwater, Nordic Tug, Grady-White) and from owners who fitted their own, 2016 to 2025. Here they are, sorted by part.

The controller has the longest thread, the one above. A British owner had "4 new controllers in 5 years" (Ian_Edwards, YBW, Sep 2016). A Nordic Tug owner wrote: "controller itself was faulty - I bought a new one on ebay for $150... The controller has some internal electronics that start to fail; apparently not an uncommon problem" (Foster Nordic, Trawler Forum, Jun 2018). In Sep 2021 an engineer traced the electronics inside the black box to a MOSFET (a kind of power transistor) and diodes (Ian_Edwards, YBW).

The corroded on a 185TT 5 kW in Apr 2016: "corrosion in the main contactor... It cost £50" (Ian_Edwards, YBW). The reason: "the contactor had got wet, actually immersed in rain water".

The seized on three 140TT motors in a row for one owner (albertan, Trawler Forum, Aug 2023). "Lewmar does not sell brushes, they do sell new motors." A replacement motor is "sold as an assembly... Price is $3,700, ouch" (a Cutwater C-32 owner, Tugnuts, Jan 2025). Brushes in Britain ran "£150+" (VicG, YBW, Aug 2025).

The : a hub that left the boat at 22 months (grahamdouglass, Trawler Forum, May 2021), a gear that "FELL OUT" of a 2019 tug (a Ranger Tug RT27 owner, Tugnuts, Oct 2020), and a gearbox "full of water and no oil" (gbgrady208, Great Grady, Feb 2025).

The size: a 60,000 lb boat's largest 12 V unit was "too small" (Insequent, Trawler Forum, Apr 2017), and a 185TT 4.0 at the stern until hoods went on (steelydon, Trawler Forum, Apr 2017).

No owner we read had a Gen 2 blue-box system fail the way the old controllers did.

Strengths and limitations

Each line names its source. Some of the limitations are findings from the maker's own documents and the stores' prices. The rest are owners' accounts, and each line says which.

What holds up

You can buy one this week. Defender, Fisheries Supply and the owner's own store list the same units with a price and stock, and the dealers host the manual, the drilling template and the fault-finding table. There is no "call for price" step and no dealer network to find first. Of the 16 Lewmar units in our database, 14 carry a Defender price; Defender lists no 250TT or 300TT, which Marinedeal sells. Published Defender rows captured 13 October 2026; Lippert and Fisheries pages read 2 October 2026
The manual prints the whole ladder on one page: part number, tunnel, motor, voltage, IP version, gearbox material, propeller, thrust in kgf and pounds, weight and fuse. A second table gives the stated current per model and voltage, the smallest cable that will carry it and the longest run at that size, with a worked example. The TT 185 6.0Kw 12v draws 700 A on 300 mm² up to 22 m; the 24 V version draws 370 A on 120 mm². Published Gen 2 manual 559231 Iss.3, sections 4.5 and 6.1, read 13 September 2026; Lewmar's Iss.5 (2020) withdrew the per-model current table for "guidance only" tables by distance, read 23 September 2026
The thruster's own manual gives a run-time rule with numbers. Run it constantly in one direction for 3 minutes and "the system will enter fault mode". A thermal switch flashes the LED red and clears itself when the motor cools, and the system powers down after 15 minutes idle. The fault-finding page says how long the cooling takes: "Wait 20 minutes for motor to cool and reset." Published Gen 2 manual, sections 4.9 and 11, read 13 September 2026
The manual's placement rules match the lever this site sizes by. Mount "As far forward as possible (Fig 3.1.1 / lever effect)", keep the tunnel 1 diameter under the waterline "to prevent air being sucked into the tunnel" (0.75 minimum), make it at least 2 diameters long, and follow a wall-thickness table per model. Published Gen 2 manual, section 3.1, read 13 September 2026
Owners on big boats say it has never timed out. The first: "I have a 185TT Lewmar 8HP. Their largest 12V unit. I have had no issues with it, but it is too small for my boat, which is around #60,000lb. If there is much wind or current it has to run a lot, but I have yet to timeout." The second, with a 24 V unit: "My Lewmar has never timed out, in a few cases with steady operation in excess of a minute." A DIY pair fitted a 140TT to a 1985 Bayfield 32C and published the whole job. Reported Insequent and sunchaser, Trawler Forum, Apr 2017; Good Old Boat, 2023
A company with a long record and a US office. Founded 1946 in Havant, Hampshire, England, three Queen's Awards, sold to Lippert Components of the United States on 1 August 2019 for £33.286 million on sales of about £55 million, with distribution from Guilford, Connecticut in its 2018 manuals (the 2020 manual prints Gloversville, New York). The Gen 2 electronics came with a "Blue Box converter", so an older installation can take the new controls without new wiring. Published About page, Lippert press release, control manual 559232, read 13 September 2026

What does not

"Three years" is one year on the parts that fail. The warranty in every manual promises 3 years, then under "EXCEPTIONS" limits cover to 1 year for "Electric motors and associated electrical equipment" and "Electronic controls". On an electric thruster that is the motor, the contactor and the controller. The tunnel leg keeps the three years. The warranty "does not cover any incidental costs incurred for the investigation, removal, carriage, transport or installation", and "Service by anyone other than authorized Lewmar representatives shall void this warranty". One owner's reading: "3 year 'parts-only warranty'". Finding Gen 2 manual section 12 and the pre-Gen 2 manual, read 13 September 2026; a Ranger Tug owner, Tugnuts, Oct 2020
The older controller ran thrusters on their own. One owner in 2017: "my bow thruster has turned on and had been running for an extended time". A second, the same year, found "the problem was with the potted electronics in the joystick assembly". A third, in 2020: "My 140TT Thruster started on it's own in the middle of the night... all the plastic components melted and it's toast - also a definite fire hazard". A 2017 Cutwater was "possessed" for a season until the dealer's mechanic "finally got Lewmar to acknowledge that there was a problem with the design of the controller". The replacement arrived "with a 'little black box' attached". Lewmar's answer is the Gen 2 electronics and a converter for older boats. The 2020 owner adds: "no one from Lewmar ever contacted me about this issue and I'm registered". Reported seabum, GoneFarrell and BobnDoc, Trawler Forum, May 2017 to Mar 2020; skiprocks, Trawler Forum, Feb 2020
No boat length from the maker, except the Small Boat TT page ("up to about 28ft" for the 110TT), and two from one dealer. Fisheries Supply prints a "Typical Boat" range on each listing: the 12 V 185TT 6.0 is 46 to 66 ft, while the 24 V 185TT 6.0, the same motor and propeller, is 45 to 55 ft. Its description line says the range "covers all boats from 30 to 150 feet". We cannot find where the bands come from. Finding Gen 2 manual; Fisheries Supply listings, read 13 September 2026
The owner's own store is the expensive place to buy. On 2 October 2026 lippert.com listed the 6 units we could match at 81% to 95% above Defender's price for the same part number, and Fisheries 26% to 35% above on the 4 it lists (our division). Parts run the same way: a replacement 140TT motor is "sold as an assembly and no brushes available - according to Lewmar. Price is $3,700, ouch." Finding lippert.com, Fisheries and the database, read 2 October 2026; a Cutwater owner, Tugnuts, Jan 2025
Brushes. One owner: "I have now had to change three Lewmar 140TT 2.2 kw bow thruster motors which suddenly stop working in all cases it appears to have been problems with the motor brushes seizing in position and corrosion on the brush carrier". From the same forums: "Lewmar does not sell brushes, they do sell new motors." A Gen 1 185TT owner: "replacement brush costs appear high @ £150+". The manual's own service line: "Brush out carbon dust from top of electric motor especially on aluminium boats." Reported albertan, Trawler Forum, Aug 2023; a Cutwater owner, Tugnuts, Jan 2025; VicG, YBW, Aug 2025; Gen 2 manual section 5
Support and parts, as owners describe them. A 185TT 6.0 whose "complete hub assembly was missing. Only the shell was left" at 22 months: "I've tried contacting Lewmar at their tecksupport email address... suing Lewmar seems like a fools errand." A 2019 Ranger Tug whose gear "FELL OUT": "hasn't responded to our claim for replacement gear-leg 'hub assembly' in over a month. It's only ~$200 part"; the owner bought it elsewhere and "had the part in hand in 7 DAYS". "they wouldn't place an order direct-to-consumer"; "Lewmar deliveries are astonishingly slow, they won't even allow you to pay for speedy freight." Against that, a gearbox "full of water and no oil" that Lewmar "replaced (part only) under warranty" in 2025. Reported grahamdouglass, Trawler Forum, May 2021; Tugnuts, Oct 2020 and Jan 2025; gbgrady208, Great Grady, Feb 2025
Two cells wrong in the manual's own tables. The hydraulic TT 250 Hyd Gen 2 is printed "200 240" for kgf and pounds, and 200 kgf is 441 lb. The current table's 250 8 KW row prints its voltage as "224". And the maker's own Gen 2 product page, where the specification should be, prints "We have no additional data for your currently selection." until an option is picked, and nothing in its markup. Finding Gen 2 manual sections 4.5 and 6.1; lewmar.com Gen 2 page, read 13 September 2026
A worked example that contradicts its own table. The example under the cable table gives the 250 8 KW 95 mm² of cable for 28 m of run. The row above it says 185 mm² to 20 m for the same unit. The example is a cell from the older manual. Finding Gen 2 manual section 6.1, read 13 September 2026
Every Lewmar goes on with the boat out of the water. The retractables on Defender: the RT185 MX Gen 2 at $8,686.99 to $9,033.99 and the 250VRTT at $29,416.99, against $1,911.99 to $3,426.99 for the 12 V 185TT ladder. The maker publishes no low-voltage thrust figure: one figure per model, with no voltage stated for it. Published Database rows captured 13 October 2026; Gen 2 manual section 6.1

Who it is for

Good fit if

You want to order this week from a chandlery, with the manual in hand. It is on the shelf at the three US stores we priced, with a price on every row and a fault-finding table on the manual's last page.

You already have one aboard. Gen 2 electronics take the place of the old controller, and a converter lets an older installation take them.

You want to fit it yourself. The 140TT has a published owner install.

You want a choice of motors. The 185TT ladder puts four motors in one housing.

You sail and will not carry a tunnel's drag. The , priced in the cost section below, suit you.

Check these first

The warranty. Read the warranty page before you count on three years, because the motor and the controls get one.

Repairs. Owners report that are not sold separately, so the motor is the replacement part.

The battery. The maker's battery guidance is a single sentence, so you size the bank yourself, with our battery calculator or your installer.

Look elsewhere if

The boat has to stay in the water for the job. Every Lewmar needs a .

The sailboat guide and the trawler guide put the 185TT beside the alternatives at each length.

What it costs, at three stores

Lewmar is the one brand on this site you can price at three US retailers on the same day. Our database and the thruster finder, our free tool that matches a thruster to your boat, use Defender's prices, captured 13 October 2026.

The other two stores charged more. On 2 October 2026 the owner's own store, lippert.com, listed the same part numbers at 81% to 95% above Defender. Fisheries Supply was 26% to 35% above on the 4 it lists. Each share is our division on that row.

These are unit prices. Every figure is the unit alone, before the , the panel where it is separate, cable, battery and labor. The cost page prints the Defender ladder with the tunnel and labor bands around it.

One unit, three prices: Defender as our database holds it (13 October 2026), Lippert's own store and Fisheries Supply as read on 2 October 2026. The shares are the other store's price over Defender's, our division.
Unit	Defender	Lippert	Lippert, above Defender	Fisheries	Fisheries, above Defender
Lewmar 140TT Tunnel Thruster Thrust 82 lbf (37 kgf) Mounting tunnel Price $1,485.99 Defender listing, read 13 October 2026. Full page: fit, cost and wiring See it on Defender	$1,485.99	$2,890.95	+94.5%	$2,012.40	+35.4%
Lewmar 140TT Tunnel Thruster Kit Thrust 82 lbf (37 kgf) Mounting tunnel Price $1,964.99 Defender listing, read 13 October 2026. Full page: fit, cost and wiring See it on Defender	$1,964.99	$3,565.95	+81.5%	—	—
Lewmar 185TT GEN 2 Tunnel Thruster Thrust 128 to 214 lbf (58 to 97 kgf) across 5 sizes Mounting tunnel Price $1,911.99 to $4,825.36 across 5 sizes Defender listing, read 13 October 2026. Full page: fit, cost and wiring See it on Defender	$1,911.99	$3,458.95	+80.9%	$2,408.36	+26.0%
	$2,338.99	$4,366.95	+86.7%	—	—
	$2,707.99	$5,199.95	+92.0%	$3,620.65	+33.7%
	$3,426.99	$6,590.95	+92.3%	$4,595.44	+34.1%

One caution on the 140TT row. Lippert's store listed its "140TT 2 kW" as part 590003, and the Gen 2 manual's ladder gives that number to the 2.2 kW unit (42 kgf). Its 2 kW unit is 590002. Defender sells the 2 kW unit as 591482 and prints no ladder number. So that row matches the stores by the motor each one names. There is no shared part number to match on. If Lippert's 590003 is the manual's 2.2 kW unit, it compares two different motors.

Every Lewmar row in our database with its US price and the store it came from, captured 13 October 2026 to 14 October 2026. The 185TT Gen 2 row runs from its 3 kW 12 V motor to its 6 kW 24 V one.
Model	Series	Thrust	Price	Store
Lewmar 110TT Thruster Kit Thrust 62 lbf (28 kgf) Mounting tunnel Price $935.99 Defender listing, read 13 October 2026. Full page: fit, cost and wiring See it on Defender	110TT	62 lb	$935.99	Defender
Lewmar 110TT 1.5 Bow Thruster Complete Package Thrust 62 lbf (28 kgf) Mounting tunnel Price $1,338.99 Defender listing, read 13 October 2026. Full page: fit, cost and wiring See it on Defender	110TT	62 lb	$1,338.99	Defender
Lewmar 125TT Tunnel Thruster Thrust 77 lbf (35 kgf) Mounting tunnel Price $1,845.99 Defender listing, read 14 October 2026. Full page: fit, cost and wiring See it on Defender	125TT	77 lb	$1,845.99	Defender
	140TT	82 lb	$1,485.99	Defender
	140TT	82 lb	$1,964.99	Defender
Lewmar 140TT Gen 2 Thruster Package with Joystick and Tunnel Thrust 92 lbf (42 kgf) Mounting tunnel Price $2,754.14 Defender listing, read 13 October 2026. Full page: fit, cost and wiring See it on Defender	140TT	92 lb	$2,754.14	Defender
	185TT	128–214 lb	$1,911.99–$4,825.36	Defender; 24 V at Fisheries Supply
Lewmar 185TT GEN 2 Tunnel Thruster Package with Joystick Thrust 128 lbf (58 kgf) Mounting tunnel Price $2,238.99 Defender listing, read 13 October 2026. Full page: fit, cost and wiring See it on Defender	185TT	128 lb	$2,238.99	Defender
Lewmar 250TT GEN 2 Tunnel Thruster Thrust 308 lbf (140 kgf) Mounting tunnel Price $4,949.00 Marinedeal listing, read 14 October 2026. Full page: fit, cost and wiring See it on Marinedeal	250TT	308 lb	$4,949.00	Marinedeal
Lewmar 300TT GEN 2 Tunnel Thruster Thrust 550 to 616 lbf (249 to 279 kgf) across 2 sizes Mounting tunnel Price $7,339.00 to $10,499.00 across 2 sizes Marinedeal listing, read 14 October 2026. Full page: fit, cost and wiring See it on Marinedeal	300TT	550–616 lb	$7,339.00–$10,499.00	Marinedeal
Lewmar RT185 MX Gen 2 Thrust 214 lbf (97 kgf) Mounting retractable Price $8,686.99 to $9,033.99 Defender listing, read 13 October 2026. Full page: fit, cost and wiring See it on Defender	RT	214 lb	$8,686.99–$9,033.99	Defender
Lewmar 250VRTT Vertical Retractable Thrust 353 lbf (160 kgf) Mounting retractable Price $29,416.99 Defender listing, read 13 October 2026. Full page: fit, cost and wiring See it on Defender	VRTT	353 lb	$29,416.99	Defender

Installed, most of the bill is labor. Two owners fitted a 140TT to a 1985 Bayfield 32C themselves. The DIY page holds that job line by line.

Repairs from the threads:

a controller at $150 on eBay
a at £50
a hub assembly at "~$200"
a 140TT motor assembly at $3,700

Our own yard estimate for the 185TT on the 48 ft sailboat row of our cost-by-boat-type table is $9,108 to $22,238 all in. The low end is the 3 kW motor with the cheapest yard hours, the high end the 6 kW motor with the most expensive. It is priced the way the finder prices a yard job.

Videos

Two of Lewmar’s own videos, from its YouTube channel: what changed from Gen 1 to Gen 2, and the older swing-down retractable in use. Lewmar’s channel has nothing on the RT185 MX Gen 2 or the TT range at work. They are the maker’s pitch. Watch them for the hardware, and take the claims to the sections above.

A still from Lewmar's video: a technician at a bench with a Gen 2 thruster motor, its control box and cables. — Lewmar’s own video, on Lewmar’s YouTube channel. The picture is a still from it.

A still from Lewmar's Swing Thruster video: a small cabin cruiser coming alongside a pontoon, seen from above. — Lewmar’s own video, on Lewmar’s YouTube channel. The picture is a still from it.

Questions to ask before you order

Most of these are answered on the manual's last three pages. Get the answer for your boat in writing before the is cut.

Which parts are on three years and which on one? The manual says the motor, the electrical equipment and the electronic controls are on 1. Ask the seller to confirm it in writing, and who does warranty work near you.

Gen 2 or older stock? The blue-box electronics are the maker's answer to the controller record above, and a converter exists for older installations. Ask which you are getting.

Which store? The same part number was 81% to 95% more at the owner's own store than at Defender on 2 October 2026.

Where did the boat-length band come from? The maker publishes none. Take our 15 knot figure in with you.

What battery, and how far from the unit? The manual gives the current and one sentence. The 12 V 6 kW draws 700 A. Ask the installer for a and where it came from.

Which voltage, 12 V or 24 V? The manual's cable table roughly halves the current at 24 V and cuts the cable to well under half: on the 6 kW, 700 to 370 A and 300 to 120 mm². The owners on big boats went 24.

Will you keep the battery switch off when you leave the boat? The manual requires it, and every owner whose thruster ran on its own says the same.

What does a motor cost when the brushes go? Owners report are not sold separately. Ask the price of the motor assembly for your model now.

Where to go next

Compare thrusters side by side Pick up to four tunnel, retractable or external units and see specs, price and fit together.
Tunnel thruster installation The eight steps of a tunnel install from the makers’ manuals, with hours for each.
Bow and stern thruster batteries Why makers size in cranking amps, where the bank lives, what sag costs in thrust.

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The prices and specs on this page are as published on the dates shown, and our yard estimate is for planning. None of it is an inspection of your boat. Check any thruster, cable or battery against the maker's manual and with your yard before you buy or fit anything. The full wording is in our terms.