Troubleshooting
Bow thrusters and insurance: what to ask your insurer
There are four things to ask about thrusters and insurance. Does an insurer require one? Does it exclude one? Does it charge more for one? Does it need to be told about a retrofit?
We went looking for a US document that answers any of those. This page shows what we read, what each document says, and what you can do while the written record stays silent. Mostly, we found nothing. That is worth knowing, because the confident answers elsewhere are not sourced either.
Where this comes from. Every page below was read on 20 September 2026. They are two insurers’ own consumer pages, one underwriter’s, BoatUS Marine Insurance’s FAQ, and two BoatUS Magazine articles. The table shows what each says about a thruster. Where a page says nothing, the table says so.
The short answer
None of the six documents names a thruster in a requirement, an exclusion, a reason to charge more, or a claim.
Progressive says many insurers will not cover a used boat that has not been surveyed. BoatUS Magazine says the surveyor checks thrusters with everything else below the waterline.
BoatUS Magazine’s claims review ranks sinking number 5 by count. It says water most often comes in through holes below the waterline. A A 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 two of those holes.
Whether your thruster is covered, and whether a retrofit has to be declared, is in your policy’s wording. Ask your insurer in writing.
The finding
None of the six documents read names a thruster in a requirement, an exclusion, a reason to charge more, or a claim. Five do not mention the word at all.
The one that does is BoatUS Magazine’s survey guide of February 2026. It names the word once, as one of the things a surveyor checks below the waterline.
We also looked for two other things and did not find them:
- published claim data that separates a thruster from any other below-waterline fitting
- an insurer page that says a retrofit must be notified or a tunnel disclosed
Be wary of confident answers. Someone may tell you an insurer will refuse a boat for an external unit, or load a premium for a tunnel. Someone may say a survey will fail one kind of thruster. We could not find any of that written down.
Your policy is a contract, and the answer is in its wording. Get a written reply from your insurer before you buy.
What we read, and what each says
| Who | Document | Date | About a thruster |
|---|---|---|---|
| Progressive | Do You Need a Survey for Boat Insurance? | updated 15 August 2023 | Not mentioned. Says some insurers require a condition and value survey and many will not cover an unsurveyed used boat. |
| GEICO | Boat Insurance for Older Boats | undated | Not mentioned. Names three age bands (over 20, 25 to 40, over 40 years) and says insurers ask for inspections, maintenance records, or proof of recent upgrades. |
| Markel | Choosing the Right Marine Surveyor | undated | Not mentioned. Names the Condition and Valuation survey and the two associations’ designations. |
| BoatUS Marine Insurance | Boat Insurance FAQ | undated | Not mentioned. Its Mechanical Breakdown Coverage applies to the lower unit of an outboard motor, or the upper and lower units of a stern drive motor. It applies on boats 10 years old or newer. |
| BoatUS Magazine | The Boat Survey | February 2026 | Mentioned once: the surveyor checks thrusters with everything else below the waterline at the haul-out. |
| BoatUS Magazine | Top 10 Marine Insurance Claims | September 2018 | Not mentioned. Sinking is the number 5 claim, and water most often comes in through holes below the waterline. |
BoatUS’s FAQ describes one machinery endorsement, and it is worth reading closely. It is the closest thing in these documents to the coverage a thruster question is about.
Its Mechanical Breakdown Coverage applies to the lower unit of an outboard motor, or the upper and lower units of a stern drive motor. It applies on boats 10 years old or newer, and to nothing else it names.
A thruster is not on that list. The FAQ does not tell us whether a thruster falls under the boat’s hull coverage as attached equipment, or under nothing at all. Ask your insurer.
What is documented: the survey
What the insurer pages do talk about is the survey on a used boat.
Progressive says “some boat insurance companies require a marine survey” for boats of a certain age, length or value. The survey it names is the condition and value survey.
Progressive also warns that “many insurers won’t cover used boats that haven’t been surveyed”.
GEICO sorts boats into older (over 20 years), classic (25 to 40) and antique (over 40). It says insurers often ask for inspections, maintenance records, or proof of recent upgrades.
Markel names the Condition and Valuation survey. It also names the two associations whose designations it looks for (NAMS-CMS and AMS).
BoatUS Magazine puts it this way: “you’ll probably be unable to finance or insure a boat without one.”
The thruster gets looked at during that survey. BoatUS Magazine again: “Surveyors also check the condition of props and anodes, thrusters and trim tabs, rudders and struts, and anything else below the waterline.”
So the thruster reaches the insurer the way everything else on the boat does. It is a line in a surveyor’s report, with a condition and a value against it. The survey page is your checklist for that day.
What is documented: the holes below the waterline
The narrower thing the record does support is about water getting in.
BoatUS Magazine reviewed five years of its own claims (2012 to 2017, published September 2018). By count, sinking ranks number 5.
Here is what the review says about the cost of those claims: “In many cases, the dollars paid out for sinking claims exceeded the payouts from hurricane claims, even though they generate several times more claims.”
It gives one sentence on where the water comes from: “Water most often finds its way in through those pesky holes below the waterline.”
And it gives this advice: “Check, squeeze, and tug on all fittings below the waterline at least once a season.”
A thruster can add those holes:
- A A 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 two of them.
- A retractable’s hatch is one.
- Some external units add a A fitting that passes through the hull below the waterline, sealed with a wide lip on each side. Cutting one means the boat comes out of the water. for the cable.
- An external mount like Sideshift, or a track-mounted pod like DockStar, adds none below the waterline: Sideshift’s strap and cable holes go through the bow above it.
The makers write their own leak checks. Sleipner’s installer signs that “The boat has been checked for water leakage around the installation.”. VETUS’s retractable manual says to check for leaks the moment the boat goes back in the water. The no-hole page lists what every product drills, from its manual.
That is the link between a thruster and a claim that the record actually supports. Check the thruster’s fittings once a season with the rest of the fittings below the waterline.
What to do with that
Ask your insurer in writing. Ask whether a retrofitted thruster needs to be declared, and whether it is covered as equipment. Ask what they require of the surveyor. Keep the reply with the policy.
Keep the paperwork. A surveyor and an adjuster will ask for the yard’s invoice, the maker’s manual and the installer’s sign-off. The install page says what the invoice should show.
Treat the tunnel as a below-waterline fitting, because it is one. Put the joint at the tube ends and the compartment’s bilge on the seasonal check, with the A valve on a fitting through the hull that shuts the sea out. Good practice, and some insurers, say to close every one of them when you leave the boat. and the hoses.
Wire it to the standard a US surveyor works to. The wiring page works through the cable, the fuse and the main switch in The 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. The 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. terms. That is the standard a US survey report works to.
Do you have an insurer’s written answer, a policy clause or a claim that names a thruster? Please send it in, and we will update this page.