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Lewmar · tunnel thruster · bow or stern
Lewmar 110TT Thruster Kit: specs, price and the boats it fits
It gives 62 lb (28 kgf) of push. Lewmar sells it for boats of up to 30 ft. It runs on 12 V.
- Haul-out to install
- DIY 2 of 5: wiring prep only
- 3-year warranty
Quick stats
- Thrust 62 lb 28 kgf, Lewmar's rating
- Boat length Up to 30 ft Lewmar's own range
- Price per lb of thrust $15.10 Unit only. $121 to $155 installed
- Voltage 12 V As sold
- Battery at 12 V 215 CCA One battery, near the thruster
- Run limit 3 min In one direction, then fault mode
- To install it Haul-out The boat comes out of the water
- Mounts Tunnel Fixed mount, bow or stern
About the Lewmar 110TT Kit
The 110TT is Lewmar’s smallest tunnel thruster: a single propeller in a slim 110 mm tube, giving 62 lb of push on 12 V, the same each way. Lewmar pitches it at small boats whose owners want help getting the bow off the dock in a breeze. Lewmar has made boat hardware in England since 1946 and has been American-owned, by Lippert, since 2019.
Defender sells this kit for $936, the lowest price of any Lewmar on this site, and lists nothing in it beyond the thruster. So plan on the tube, a control panel, a fuse and the battery switch Lewmar says every installation must have, about $419 to $911 in all. One starting (cranking) battery near the thruster runs it; with cable and a charger we put that at $498 to $574. See every part.
Read more
The controls stop the motor after three minutes of pushing one way, and a thermal switch makes you wait for it to cool. The 110TT has a composite hub with no zinc anode, so there is no zinc to change each year. Lewmar’s warranty reads three years, but the motor and the controls get one.
The full spec sheet for a yard sits lower down, and the Lewmar thruster review covers Lewmar’s whole range.
Where this summary comes from (6 sources, read 13 October 2026)
- Defender listing (the database’s price)
- Defender, 110TT complete package listing (composite hub, no zinc anode)
- Lewmar, Small Boat TT electric thruster
- Lewmar Gen 2 TT installation manual 559231 Iss.3 (three minutes one way, then fault mode; warranty one year on motors and controls)
- Lewmar, About (making boat hardware in Havant, England, since 1946)
- Lippert Components acquires Lewmar Marine Limited, 1 August 2019
Will the Lewmar 110TT Thruster Kit steer your boat?
31 FT TRAWLER · BOW · 15 KT WIND
Every knot figure here is wind speed, not boat speed or current.
On a 31 ft trawler the Lewmar 110TT Thruster Kit (62 lb) steers her in a 15 knot breeze. Her bow needs about 65 lb from a tunnel to steer her in a 15 knot breeze. Its 62 lb lands within 15 percent of that figure, which this site counts as enough.
The finder lists it for her.
The Lewmar 110TT Thruster Kit on a trawler, by length
- 25 ft18 kt
- 30 ft15 kt
- 35 ft13 kt
- 40 ft12 kt
- 45 ft10 kt
- 50 ft9 kt
- 55 ft8 kt
- 60 ft8 kt
- 65 ft7 kt
- 70 ft7 kt
- 75 ft6 kt
- 80 ft6 kt
Outlined: the finder does not list it at that length (under 13 kt, far more than she needs, or outside Lewmar’s own length range).
- Under 10 kt
- 10 to 15 kt
- 15 to 20 kt: the sweet spot
- Over 20 kt: more than she needs
Prices are the low end of the installed total, from our estimate. For your own boat, drive and installer, the finder prices each unit.
Is it right for your boat?
Every kind of boat it fits, by length
| Boat | Full thrust at 15 knots | Still a fit, in lighter wind |
|---|---|---|
| Pontoon & tritoon | Not listed. A pontoon has no hull body between the logs to bore a tunnel through, and nobody sells one for these boats. | |
| Sailboat | 23 to 31 ft | 32 to 33 ftfull thrust to about 14 knots at 33 ft |
| Houseboat | No length. Short of the thrust the boat needs. | |
| Catamaran | 30 to 33 ft | None |
| Trawler | 23 to 31 ft | 32 to 33 ftfull thrust to about 14 knots at 33 ft |
| Motor yacht | No length. Outside the maker's length range. | |
| Bass & flats | Not listed. Nobody sells a tunnel kit for these hulls, and a bass boat’s shallow planing bow has almost no depth to hold one. | |
| Wake & ski boats | Not listed. Nobody sells a tunnel kit for these hulls. | |
| Express cruiser | 28 to 33 ft | None |
| Center console | 32 to 33 ft | None |
The Lewmar 110TT Thruster Kit against each kind of boat, in a 15 knot wind. Our sizing, from the finder’s own rules.
The first column is where one unit gives all the thrust the boat needs in 15 knots. The second is where the finder still lists it: the unit steers her in a 13 or 14 knot wind, within 15 percent of the 15 knot breeze this site sizes for. On a boat shorter than the first column’s shortest length, the unit is more than the boat needs.
How we size it
Our figure is the longest boat one unit can steer in a 15 knot wind. It is a range because each kind of boat catches the wind differently. Here a sailboat gets full thrust to 31 ft, and a catamaran to 33 ft. The maker gives one range for every boat.
The table tries the Lewmar 110TT Thruster Kit on each kind of boat, at every length that kind of boat is built in. The wind is 15 knots and the rules are the finder’s own. A length counts as a fit when the unit gives the thrust that boat needs at the bow and the maker lists it for that length.
A boat up to 10 percent past the maker’s range still counts here, as it does in the finder. So the table runs up to 33 ft, just past Lewmar’s own range (up to 30 ft).
It is sized for five kinds of boat here. For your own boat, the finder gives an answer that also counts your drive and who does the installing. The compare page sets this unit beside others.
What it costs installed
A yard job, everything in. Our estimate.
| Boat | Total installed |
|---|---|
| 23 ft | $7,383 to $9,291$119 to $150 a lb of thrust |
| 30 ft | $7,513 to $9,631$121 to $155 a lb of thrust |
| 33 ft | $7,563 to $9,771$122 to $158 a lb of thrust |
From the shortest to the longest boat it is sized for.
What is in each total
These totals are our estimate of a yard job: the unit’s price, plus a yard’s hours at $160 to $180 an hour, plus the batteries, cable and charger, plus the other parts the box does not hold. A Lifting 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. adds $410 to $1,590 at these lengths, with 5 to 7 days out of the water, worked from eight yards’ own rate cards. The hours come from what owners and yards report. The cost page builds the same figures line by line.
| Boat length | The unit | Yard labor | Haul-out | Batteries, cable, charger | Other parts |
|---|---|---|---|---|---|
| 23 ft | $936 | $5,120 to $5,760about 32 hours | $410 to $1,110 | $498 to $574 | $419 to $911 |
| 30 ft | $936 | $5,120 to $5,760about 32 hours | $540 to $1,450 | $498 to $574 | $419 to $911 |
| 33 ft | $936 | $5,120 to $5,760about 32 hours | $590 to $1,590 | $498 to $574 | $419 to $911 |
For every length in the table above.
How the batteries, cable and charger add up. We price a battery bank close to the thruster, as the makers recommend, with 10 to 20 ft of cable out and back: red for the positive, black for the negative, cut to length. The low end is the cheapest battery that meets the figure and the shorter run; the high end is a sealed (AGM) battery and the longer run. The charger is a NOCO GEN5X2 two-bank shore charger.
Batteries and lugs are priced at Fisheries Supply and the cable and charger at Defender, read 26 October 2026.
- At 12 V: one 12 V battery, at least 215 CCA (Lewmar’s minimum), $257 for the battery; Lewmar’s cable table gives 1/0 AWG: $95 to $171 for the red and black cable and the lugs; a GEN5X2 charger, $146.
The sizing and the costs on this page are estimates, for guidance only and without warranty. They are no quote, and nobody has inspected your boat. Check them against the maker’s manual and your yard before you rely on them. Terms of use.
DIY breakdown
DIY levels
- Level 5: Owner install. No yard, no electrician.
- Level 4: You install 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 installs the unit and does the hull work; you do the wiring prep.
- Level 1: Yard job. A qualified professional does all of it.
You Yard Electrician. The bar is labor hours; a haul-out is a note.
How we rate DIYYou: 4 to 16 hours Yard: 32 to 70 hours Electrician: 2 to 4 hours Plus a haul-out.
Your part needs:Heavy battery cableCrimping big lugs
Every step, and who does it
- Cut, bond and fair the tunnel; fit the gear leg, motor and propeller Yard 32 to 70 hours The low end is two crew over two days, the job as owners describe it on the forums. The high end rises with boat length between two real billed figures: 32 hours at 35 ft, and the largest invoice we hold, 70 hours at 47 ft.
- Mount the battery box, switch and fuse holder; run and secure the cables You 4 to 16 hours Our estimate. No maker times this step, and a first-time owner is slower than a yard, so the range is wide.
- Final connections at the battery and the motor, load test Electrician 2 to 4 hours Our estimate. Nobody publishes a time for the final connections and test on their own.
A qualified marine electrician should make the final connections and test them before first use. Hours are labor only.
Related videos
One from Lewmar’s own channel and one from other channels. Each one is labeled. They play from YouTube only when you tap. Take any claim in a video back to the figures on this page, which are the ones we checked.
Know before you buy
What sets this model apart, what it costs to keep, and what to weigh.
Price per pound of thrust
$15.10 a lb The unit’s price over its published thrust. The bars are Lewmar’s next sizes and the nearest other makers.Controls
The solenoid, the ICU control box and a 2 m motor loom are in the box. The panel, its loom, the fuse and holder are bought.
- Lewmar Simple joystick, for 591101 and 591482 only (589094), $324.43 at Fisheries Supply.
- Lewmar 4-wire control cable, 2 m (589021), $38.46 at Fisheries Supply.
Service and warranty
Lewmar gives 3 years, but 1 on electric motors and their electrical equipment and on electronic controls. Service by anyone but an authorized Lewmar representative can void it. Removal, transport and installation costs are not covered.
See Lewmar’s warranty Lewmar's Gen 2 installation manual.Special mentions
Battery: at 12 V it wants one battery of 215 CCA or more, Lewmar's figure. The cheapest that meets it is the Lifeline GPL-1400T AGM starting, $256.72. Check your own bank.
Charger: a NOCO GEN5X2 two-bank shore charger, $146.41. It is the one our estimate prices.
Lewmar sells it for either end, so it can go at the bow or the stern.
Dealer prices at Fisheries Supply, read 26 October 2026.What to weigh
The boat comes out of the water to install it: it needs a tunnel bore below the waterline.
Short pushes only: Lewmar rates the motor for 3 min at a stretch.
Parts for the Lewmar 110TT Thruster Kit
See the Lewmar 110TT Kit manualSearch for the number as printed here, with no spaces. Prices are each dealer’s on the day shown, before shipping and tax. Check the plate on your motor before you order: some parts change with the tunnel size, the voltage or the year.
For the install what the box leaves you to buy
The manual button above opens it a dealer's copy (the maker publishes none we could find). It has the hull, wiring and fuse figures for this model.
From Lewmar’s Gen 2 TT installation manual 559231 and the RT manual 55110070, Iss.3 and Iss.4, read 30 September 2026.
- In the box
- The motor, the solenoid and its loom, the ICU control box, a 2 m motor loom, the saddle, gasket, hub, propeller, anode kit and fixings. The RT ships with its own housing and actuator.
- Bought separately
- Under Accessories: the control panels, the panel looms, the fuse holders and ANL fuses, the automatic battery switch. "The installation MUST have a battery switch". The tunnel fits a Lewmar saddle.
- Charging
- The manual sizes the battery by cranking amps and says to "ensure batteries are fully charged before switching on the main power". It gives no rule on a charger, a feed or a bank of its own.
The manual’s words, page 12: “Battery crank capacity should be at least equal to the thruster current.”
The “other parts” line in the estimate above covers these parts as a range, $419 to $911 at Fisheries Supply’s prices on 30 September 2026 and 26 October 2026, because the exact items depend on your boat. The batteries, cable and charger have a line of their own. The cost page has what every maker says about each part.
Tunnel tube
Fisheries Supply lists it as “VETUS fiberglass tunnel tube, 110 mm bore, 30 in”.
Sold in lengths from about 30 to 40 in. This is the shortest: the yard cuts the tube to the width of your hull at the thruster. No Lewmar tube is listed at this bore. This one is another maker's.
Control panel
Fisheries Supply lists it as “Lewmar Simple joystick, for 591101 and 591482 only”.
Control cable, panel to thruster
Fisheries Supply lists it as “Lewmar 4-wire control cable, 2 m”.
Sold in lengths from 2 to 22 m. This is the shortest: measure the run from the helm to the thruster and buy the length that reaches.
Main fuse
Ask for 200 A (Lewmar 589012).
Lewmar's figure for the 590000, TT 110 12v (Gen 2 installation manual, Iss.3). Not listed at Fisheries Supply; ask a Lewmar dealer.
Fuse holder
Ask for Lewmar fuse holder 589006 (T1) or 589013 (T2).
Ask the dealer who sells the fuse.
Battery switch
Fisheries Supply lists it as “m-Series 300 A battery switch, on/off”.
Rated at or above the 200 A main fuse. If your manual names its own switch, use that one.
Batteries
Fisheries Supply lists it as “Lifeline GPL-1400T AGM starting”.
One at 215 CCA or more. The cheapest listing that meets it.
Battery cable, red and black
Defender lists it as “Ancor tinned battery cable 1/0 AWG, cut to length, red or black”.
You need 10 ft of each color. For about 20 ft of cable in all, out and back. Measure your run and check it against the cable table in the manual: never go smaller than it asks for.
Cable lugs
Fisheries Supply lists it as “Tin-plated starter lugs, 1/0 AWG, bag of 10”.
The listing runs $23.74 to $28.04 by stud size. Eight ends on one run, with two spare.
Charger
Fisheries Supply lists it as “GEN5X2 on-board charger, 10 A, 2 banks”.
Or a DC-to-DC charger from the house system: ask the electrician.
Outside the hull replacement parts in the water
Propeller
The propeller on the drive. Lewmar calls it “PROPELLER AND WASHER”.
Drive pin (breaks to protect the drive)
The pin that locks the propeller to its shaft. Lewmar calls it “DRIVE PIN”.
Tunnel gasket
It keeps water out of the joint it sits in. Lewmar calls it “TUNNEL GASKET”.
Inside the boat replacement parts on board
Solenoid (the motor switch)
The heavy switch that sends battery power to the motor. Lewmar calls it “SOLENOID 2.0”. This one is for the 1.5 kW and 2.0 kW version.
The 140TT 2.2 kW takes B11126 instead. The 110TT list prints it as SOLENIOD.
Controller box (the ICU)
The electronics that run the motor when you press the panel. Lewmar calls it “GEN2 TT ICU”.
The 250TT parts list prints its ICU as 589834, the same number as its solenoid loom, so we list no ICU number for the 250TT.
Main fuse, 200 A
The main fuse at the battery, in the rating the maker gives. Lewmar calls it “200 A ANL TYPE FUSE”.
The rating the manual gives for each model it fits. Lewmar sells it as an ANL fuse.
Control panel, dual joystick (bow and stern)
The control at the helm. Lewmar calls it “Controller, Dual Joystick”.
Control panel, dual pad (bow and stern)
The control at the helm. Lewmar calls it “Controller, Dual Pad”.
Control panel, single joystick
The control at the helm. Lewmar calls it “Controller, Single Joystick”.
Control panel, single pad
The control at the helm. Lewmar calls it “Controller, Single Pad”.
Replacement motor
The electric motor that turns the propeller. Lewmar calls it “MOTOR ASSY”.
The standard motor. The manual lists a separate IP (ignition protected) motor.
No part matches. Try the number without spaces, or the part’s name.
The install parts are matched to Lewmar’s own figures and priced at Fisheries Supply, with the battery cable at Defender, cut to length.
Spare part numbers come from Lewmar’s parts pages and manuals. A dealer may sell a part we have not priced. Search for the number.
Other sizes and close alternatives
- Size up Lewmar 125TT 77 lb · $1,846
- The complete package Lewmar 110TT 1.5 Complete Package 62 lb · $1,339
- Other maker Sleipner SE25/110S 66 lb · $1,485
- Other maker VETUS Bow Pro 301 66 lb · $2,857
- Other maker Quick BTQ 110 55 lb · $2,184
The other makers listed are the nearest match each makes, of the same style and for the same end, within a quarter of its thrust. The compare page lists every model, and the thruster index lists every model with a page here.
For the yard and the installer
Every published figure, with its source.
Full spec sheet
| Thrust and motor | |
|---|---|
| Thrust | 62 lb (28 kgf) As printed: 62 lbf |
| Motor | 1.5 kW |
| Voltage | 12 V |
| Run limit | 3 min in one direction, then fault mode |
| Installation | |
| Type | Tunnel, fixed mount |
| End of the boat | Bow or stern |
| Tunnel diameter | 110 mm |
| What it does to the hull | Tunnel bore below the waterline |
| Haul-out to install it | Yes |
| Maker’s boat length | Up to 30 ft |
| Price and ordering | |
| Price | $936 full kit, a dealer's price, defender.com, 26 October 2026 |
| Part number | 59110112 V |
| Documents | |
| Manual | Installation manual (PDF)a dealer's copy (the maker publishes none we could find) |
| The site’s review | Lewmar thruster review |
Every published figure the site holds for the Lewmar 110TT Thruster Kit, with where each came from.
Draw, cable, fuse and battery at each voltage
These are the maker’s own figures, at each voltage it is sold at. The cable is the size for the shortest run in the maker’s table. A longer run may need heavier cable, and the wiring calculator works that out for your own boat.
| Voltage | Draw | Maker’s cable | Fuse | Battery | Run limit |
|---|---|---|---|---|---|
| 12 V | 215 Anominal draw | 1/0 AWG, the one size Lewmar gives for this model, for any run up to 39 ft of cable counted out and backGen 2 installation manual, Iss.3 | 200 AGen 2 installation manual, Iss.3 | Crank capacity at least the 215 A draw, Lewmar's ruleLewmar Gen 2 installation manual | 3 min in one direction, then fault modeGen 2 installation manual |
The Lewmar 110TT Thruster Kit’s draw, cable, fuse, battery and run limit, as the maker publishes them.
- At 12 V: size the cable for your run, or check the battery you have.
The tunnel: length and depth rules
Tunnel length. A minimum suggested tunnel length of twice the diameter. Lewmar’s installation manual.
Depth below the waterline. One tunnel diameter below the waterline to keep air out of the tunnel, with 0.75 of a diameter the minimum. Gen 2 TT installation manual, 559231 Iss.3 (2018).
Our notes from the manual and listings
In the box: The solenoid, the ICU control box and a 2 m motor loom are in the box. The panel, its loom, the fuse and holder are bought.
Our note
The smallest Lewmar, single propeller in a 110 mm tunnel, sold as a kit. The Gen 2 manual rates it 28 kgf (62 lb), with a composite gearbox, 10 kg and a 200 A fuse. It gives 215 A at 12 V on at least 50 mm² cable to 12 m of total run, battery to thruster and back.
That fuse sits below the stated draw, as on every row of the manual's table. Lewmar's whole battery rule is that crank capacity should at least equal the thruster current. Run it in one direction for more than three minutes and the system enters fault mode. A thermal switch stops a hot motor, and the manual says wait 20 minutes. The panel powers itself down after 15 minutes idle.
The tunnel goes one diameter below the waterline (three quarters at minimum) and at least two diameters long. The anode is checked after three or four months on a new install, then yearly. The manual says brush the carbon dust out of the motor, especially on an aluminum boat. Three years' warranty on paper, but one year on electric motors, associated electrical equipment and electronic controls.
Service by anyone but an authorized Lewmar representative voids the warranty, and removal and reinstalling are not covered. Lewmar's own page puts it on boats up to 30 ft (its spec table; its description says about 28 ft). Defender's price was captured as a five-percent-off figure. Lewmar makes its stern tunnel kits for the 140TT and up, none for the 110TT.
Where each point above comes from
- Lewmar sells it for either end, so it can go at the bow or the stern.The maker's listing
- The boat comes out of the water to install it: it needs a tunnel bore below the waterline.The mounting: a bore through the hull, or a housing recessed into it
Not sure this is the one? The thruster finder asks about your boat and prices every unit that fits.