What a bow thruster actually costs

The short answer, by boat length

Professionally installed tunnel thruster, US market, one end of the boat. These are ranges, not quotes. The confidence column is the honest part: it tells you how much data sits behind each row.

Why the forum thread you found is probably wrong

Most of the thruster cost discussion on the internet was written between 2009 and 2016. Yard labor has roughly doubled since. In January 2021 a Florida yard doing thruster work published tiered rates of $70, $80 and $90 an hour depending on the trade. By 2025 owners in the same state were reporting $175 an hour, and published Northeast fiberglass rates had reached $180.

That last row is the useful one. It is the same kind of yard doing the same job, four years earlier, at half the rate. If you are reading a 2014 thread where somebody paid $7,000, the honest translation into 2026 money is not $7,000 plus inflation. The labor line roughly doubled and the labor line is most of the bill.

What is actually inside the quote

Here is a 35 foot boat, professional tunnel install, built up from published component prices and current yard rates. This is a reconstruction rather than a single real invoice, and it is here so you can argue with your own quote line by line.

Read the two columns as what they are. The low figure is every single line landing at its cheapest and the high figure is every line landing at its dearest, so the real spread is narrower than $9,690 to $12,265 suggests. Very few jobs come in at either extreme. The middle of that range is the number to plan around.

The thing worth staring at is the tunnel tube line. A 185mm fiberglass tube lists for $265.94 at 40 inches. The most expensive tunnel tube VETUS sells, 250mm at 60 inches, is $580.10. Everything costly about a tunnel thruster is the labor of putting a cheap tube into your hull.

What the hardware lists for on its own

VETUS BOW125, BOW160 and BOW220 are listed by US retailers as special order with no price shown. We are not going to interpolate a number for them.

That SE100 row is worth a second look, because it is the clearest published illustration of something the rest of the industry keeps quiet. The same thruster makes 256 pounds of thrust at 12 volts and 220 pounds at 10.5 volts. A volt and a half of sag costs you 14 percent of your thrust. That is why the cable and battery line in your quote is not the place to save money.

Lewmar sits in the same territory, roughly $1,300 to $4,800 depending on model and retailer, with the 140TT around $1,470 to $1,820 and the 185TT Gen2 range topping out near $3,720. We have left Lewmar out of the table above for one reason: not one of the four US retailers we checked publishes a thrust rating in pounds for these units. They list kilowatts and horsepower only. You cannot compare a Lewmar to a VETUS on published data, and we are not going to convert horsepower into thrust to paper over that.

Also worth knowing: West Marine has effectively exited tunnel thrusters. Their VETUS product pages are still live but show no price and no stock. Max Power and Jet Thruster publish no US model-level pricing at all; Jet Thruster's US dealer lists every model as call-for-price.

The seven things that blow a quote up

Two boats the same length can quote thousands apart, and it is almost never the thruster that explains the gap.

1. Access. The tunnel goes where the tunnel goes, and quite often a holding tank, a V-berth sole or a bulkhead is already there. One owner's yard spent as many hours moving a holding tank back two feet and rebuilding the forward sole as it did on the actual glasswork.
2. A cored hull. The core has to be dug back around the penetration and the exposed edges sealed solid, or you have built a water path into your laminate. That is extra hours now and a hull repair later if it is skipped.
3. Thick laminate. One documented install hit an inch of solid hull and got through it only with a carbide bit in two half-inch passes. The large hole saws alone run around a thousand dollars.
4. A fine bow. The tunnel wants to be as far forward as possible for leverage but at least one tunnel diameter below the waterline. On boats with fine forward sections the point that is deep enough is too far aft to be much use, or too narrow to take the tube. This is where jobs get expensive or get refused.
5. The battery, done properly. A thruster needs its power close. Running a long cable from the engine room to the bow is the cheap way and it costs you thrust through voltage drop. Done right you get a second battery bank forward and its own charger, which is roughly $1,000 in batteries plus a few hundred for the charger, plus the labor to fit both.
6. Boat length, through the cable run. The same thruster costs more to install on a 50 footer than a 35 footer because the heavy cable run is longer and often has to go up a gauge.
7. Joystick integration. Adding joystick control to one documented Grand Banks 42 job cost $4,800 for the hardware and about $5,000 to install, roughly doubling a $12,000 to $14,000 thruster job.

What owners actually paid

The single most useful thread we found is a 2021 one from the owner of a 35 foot Intrepid, because he posted both the quote and what he did about it.

“Materials $4200 (expected), labor estimate $10k (bit of a shock). I was thinking $10k all in.”

Owner of a 35 ft Intrepid, The Hull Truth, January 2021

He then did what more people should do, which was to reverse the labor number back into hours. At the yard's own published top rate of $90 an hour, a $10,000 labor estimate meant 111 hours of work on a job the trade generally does in two to four days. Other owners in the thread put it at two days for two men. Five days later he posted that he had gone to a different yard and paid $9,200 all in.

The cheaper route, and what it costs you

External units bolt on instead of being glassed in, which removes most of the labor. Sideshift is the only maker in this category publishing open US prices, so it is the one we can quote precisely: SS230 at $4,900 for boats to 30 feet, SS240 at $5,445 to 35 feet, SS350 at $5,990 for 35 to 50 feet, ST350 stern from $5,990. Those are complete kits including the controller, joystick, harness, fuse and battery switch.

The hardware costs more than a comparable tunnel unit. The install costs a fraction. The clearest evidence is one owner who priced both routes on the same 41 foot Formula: about $25,000 quoted for tunnel thrusters at both ends, against $9,000 to $11,000 for Sideshift units he fitted himself, batteries included.

That is a real saving and it comes with real trade-offs, including thrust per dollar, an appendage in the water, and appearance. We have written those up honestly, including which products genuinely avoid a hole in your hull and which ones only say they do.

How to read a quote you have been handed

1. Ask for it split into materials and labor. If the yard will not split it, that is information.
2. Divide the labor figure by the yard's own hourly rate. If the answer is more than about 40 hours for a straightforward hull, ask what the extra hours are for. There may be a good answer, like moving a tank.
3. Check the materials line against the tables above. Roughly $4,000 to $5,500 is normal on a 35 to 40 foot boat for parts complete.
4. Confirm the battery arrangement. A dedicated bank near the thruster is the right answer. A long run from the engine room to the bow is the cheap one and you pay for it in lost thrust every time you use it.
5. Ask what size unit they specced and why. If the answer is your boat's length, push back.
6. Get a second quote. The 35 foot Intrepid owner saved $5,000 doing exactly that.

Where this data is thin

Being straight about the gaps is the only thing that makes the rest of the page worth trusting.

• Boats under 25 feet have no usable cost data at all in the US forum record.
• Post-2022 professional tunnel installs are rare in the record. Most of the corpus is 2009 to 2016, exactly the period whose labor rates have since doubled.
• Bow and stern are often not separated in reports. Where they are, stern came in about 12 percent cheaper on the same boat.
• We have yard labor rates for Massachusetts, Washington, California and Florida, but no matched thruster quotes across regions on comparable boats. So we cannot give you a regional multiplier, and anyone who does is guessing.

Hardware prices captured 24 August 2026 from Defender, Fisheries Supply, Mauripro, Hodges Marine, Boat Gear USA and Sideshift. Owner-reported figures come from dated posts on The Hull Truth, Trawler Forum, Sailboat Owners, Bayliner Owners Club, C-Brats and Sam's Marine. Yard rates from published rate cards at Crocker's Boat Yard, SEA Marine and Berkeley Marine Center.