DIY thruster installation: what you can do yourself, bow or stern

The short answer

Decide who does the work in four steps

1. Find out which installs your boat takes. The thruster finder, our free tool that matches a thruster to your boat, lists every unit that fits. You can sort the results by what you can fit yourself.
2. Read what the job asks of the hull. Check whether it goes below the waterline and whether the boat has to come out. The table under “Which installs can you do yourself?” rates each one.
3. Decide which parts are yours. On a tunnel, keep the battery, the cable run and the controls, and pay the yard for the hole. The split-job section shows what that saves, and the last section lists the reasons to hand it all over.
4. Size the wiring from the maker’s draw, then have it checked. The cable and the fuse come from the amps the maker states for your model. “What you should still pay for” has the tools to check a professional’s answer against.

Which installs can you do yourself?

Each row rates the job on four things. What does it do to the hull? Does the boat have to come out? What wiring goes into her? Whose hours are they?

The thruster finder prices from these same rows.

How to read the DIY level and bar

Every thruster on this site carries a DIY level, from 5 down to 1, and a bar. You will find them on each model’s row in the finder, on its own product page and on the compare page, where you can filter and sort by them.

The bar is the labor on the job, split three ways: you, the yard and a marine electrician. Each part is as wide as its hours. A haul-out is written beside the bar, never drawn in it, because it is time on the hard, not work anyone does.

You Yard Marine electrician

One real model at each level

What sets the level

• Level 5, owner install. No yard, no electrician.
• Level 4, you fit it, electrician connects. You mount and wire it; a marine electrician makes the final connections.
• Level 3, split with the yard. The yard does the below-waterline part; you do the wiring.
• Level 2, wiring prep only. The yard fits the unit and does the hull work; you do the wiring prep.
• Level 1, yard job. A qualified professional does all of it.

The level comes from who has to do which step, never from a percentage. So it does not move when an hour figure does. A model whose maker says only qualified personnel may install it is a level 1, whatever your skills.

Jet Thruster is a level 1 on our rating, not its maker’s: its manual does not say who must install it, but all three holes are cut below the waterline and the pump and nozzles have to sit at exact depths under it. It publishes no install hours, so its rating shows no bar.

Where the hours come from

Where a maker prints an install time, the bar uses it as printed: DockStar’s one to three hours, Sideshift’s six to eight. Where no maker times a step, the hours are our estimate and say so. Your wiring prep is 4 to 16 hours, wide on purpose, because a first install is slower than a yard’s. The electrician’s final connections and test are 2 to 4 hours. The yard’s hours are the ones our cost estimates bill.

The bar and the tables on this page count different things. The bar times the steps. The tables price the whole job the way a yard bills it, so their hours can run higher. On a fixed-mount external the bar shows Sideshift’s own six to eight hours, and the tables show 8 to 20.

Owners’ real hours will replace our estimates. Once 3 owners have reported the same step, their range takes the estimate’s place on every page. Send us your quote or your hours.

What your hours are worth

The saving on any thruster install is the labor. You buy the same hardware either way.

The table below prices the hours a yard would bill for each kind of job. It uses the same $160–$180 rates our cost page documents.

Tunnel hours come from itemized owner reports. The external figures are worked back from the makers’ own published ranges. The retractableA thruster that lives inside the hull and drops down through a hatch when you press the button, then pulls back up. It leaves no permanent hole in the water flow. hours are our arithmetic, because nobody publishes any. The in-water external models also skip the haul-outLifting the boat out of the water on a travel lift or a trailer so work can be done below the waterline. It is billed separately from the job itself. figure above. On a tunnel you pay that whoever does the work.

The afternoon job: a removable thruster

DockStar’s Smart Thruster rides on a track you screw to the hull above the waterline. The unit itself is completely self contained. It has its own battery, its own motor and a wireless remote. Nothing is wired into the boat.

Their Buyer’s Guide puts the job at one to two hours. Their About page says two to three. The user manual and the installation guides give no time. A yard would bill $160–$540 for those hours, and there is no haul-outLifting the boat out of the water on a travel lift or a trailer so work can be done below the waterline. It is billed separately from the job itself..

You mount the track and slide the thruster on. Then you steer her into the slip with the remote in one hand. DockStar’s installation kits and guides are on their site. Owners have been posting about theirs on the trawler forums since 2018.

The weekend project: a fixed-mount external

A Sideshift bolts to the hull and stays there. The company built its whole pitch around owners doing the work.

Their own installation page says the average install runs “6 to 8 hours per thruster.” It says “no previous experience or special tools are required.” And it says every model “can be installed in-water since all the mounting locations and cable connections are routed above the waterline.”

The install manuals are on that page as PDFs. You can read the whole job before you spend anything.

Owners back the pitch up with receipts. Comodave on Trawler Forum self-installed a SideShift for $4,500 in parts. The owner of a 41 ft Formula fitted external units at both ends himself, for about $11,000 all in.

He put times on it too. The bow took two people a day and a half, and the stern took one day. On the wake boat side, the one documented ezDrive install ran about ten hours.

That is the shape of the job in the reports we read: a weekend, a friend to help, and lunch for the friend. Our 8 to 20 hours in the tables above is a different figure. We worked it back from the installed-price range Sideshift publishes, set against its kit prices, so it is the whole job as a yard bills it. That is why it starts where the maker’s own six to eight ends and runs well past it.

The wiring is simple to understand: two heavy cables, a fuse at the battery end and a control wire. The cable is much heavier than anything else on the boat. What gauge and what fuse is worked out on the wiring page.

What you keep is the $1,280–$3,600 of labor. On the in-water models you also keep the haul-outLifting the boat out of the water on a travel lift or a trailer so work can be done below the waterline. It is billed separately from the job itself.. If your boat lives on a trailer, the job gets easier still. The wake and ski boat page covers that version of it.

The tunnel: read this before you pick up the jigsaw

Owners have cut their own tunnels. Two of them fitted a Lewmar 140TT to a 1985 Bayfield 32C and published the entire project at $2,367.90. Our Lewmar review reads that unit’s manual.

Cutting the tunnelA tube bored straight through the hull below the waterline, with a propeller in the middle of it. It is the conventional thruster. Fitting one is mostly a labor job rather than a hardware one. is the part of the job to respect. It is a symmetrical hole through both sides of the hull. It sits below the waterline, on the centerline, through structure.

If the urge to do the work yourself is what brought you here, a tunnel is the wrong job for it. The 32–70 billed hours happen with the boat out of the water, on a yard’s schedule. There is glasswork in the middle that a surveyor will inspect someday.

Experienced owners split it. They do the battery, the cable run and the controls themselves. They pay the yard for the hole, the bonding and the fairingSmoothing a repair or a fitting into the shape of the hull with filler, so the water flows past it without a step. On a thruster it is the work that rounds the tunnel mouth into the hull..

A retractableA thruster that lives inside the hull and drops down through a hatch when you press the button, then pulls back up. It leaves no permanent hole in the water flow. is all of that plus a moving part in the hull bottom. It is a yard’s job.

Each of these has its own page: what the tunnel job involves, step by step, what tunnel jobs cost and how to check a tunnel quote.

The split job: your wiring, their hole

On a tunnelA tube bored straight through the hull below the waterline, with a propeller in the middle of it. It is the conventional thruster. Fitting one is mostly a labor job rather than a hardware one. the labor is where the money goes. In the split, you buy and fit the battery bank, the cable run and the controls. The yard cuts the hole, bonds the tube and fairs it.

The parts you buy

The batteries, cable and charger run $483–$4,767 across the tunnel units on this site. Each product page counts them for its own unit: how many batteries the bank takes, how big, the maker’s cable and a charger. Buy them yourself and you pay retail, rather than the yard’s marked-up price for the same parts.

The hours of routing that cable through the boat are yours too. A yard would bill them at $160–$180.

No yard publishes what those hours are worth

None we found itemizes the electrical hours of a tunnel job separately from the glasswork. The 32–70 hour figures above are the whole job.

The one itemized breakdown we hold is a houseboat job from December 2016. It put the electrical at 67–75% of the itemized lines, depending on which of the owner’s two hull figures you take. That share is parts by dollars, on a hull where the tube was welded and there was no glasswork. The breakdown shows what a bill looks like. It says nothing about your own hours.

What you should still pay for

Pay for an hour of a professional checking the cable gauge, the crimps and the fuse before the first run. These tools give you something to check that professional’s answer against:

• The wiring page gives the gauge and the fuse rating from the maker’s own stated draw and ABYCThe American Boat and Yacht Council, the body that writes the standards US boats are built and wired to. A surveyor or an insurer who asks whether wiring is to standard means ABYC’s. E-11The American Boat and Yacht Council’s standard for electrical systems on boats, the one US surveyors and insurers check wiring against. Its tables set the most current each cable size may carry and the most voltage a run may lose..
• The wiring calculator does the same for your own draw and distance.
• The battery calculator gives the battery the maker asks for, in cold cranking ampsCold cranking amps: how much current a battery can deliver in a short, hard burst, which is the rating starter batteries carry. A thruster draws like a starter, so the makers size its battery this way rather than by capacity., for your own model.
• The battery page says where the makers want it.

When DIY is still the wrong answer

Not sure which of these installs your boat even takes? The finder sorts it in about a minute. You can sort the results by what you can fit yourself.