Thrusterpedia

Which boat thruster, what it costs, how to get it installed

We may earn a referral commission from some links on this page. It doesn't change your price or our recommendations.

Drawing of a tunnel thruster: a tube through the bow below the waterline, the hull cut away to show the motor on top.
Our drawing of a tunnel thruster, the same for every maker. It is not Sleipner’s own design.

Sleipner · tunnel thruster · bow or stern

Sleipner SE150/215T-24V: specs, price and the boats it fits

It gives 400 lb (181 kgf) of push. Sleipner sells it for boats of 44 to 64 ft. It runs on 24 V.

The unit$5,895Equipment only, Defender, read 26 October 2026
Installed by a yard, 55 ft boat$14,016 to $24,044Our estimate: the unit, labor, haul-out, battery and parts
  • Haul-out to install
  • DIY 2 of 5: wiring prep only
  • 2-year warranty

Quick stats

  • Thrust 400 lb 181 kgf, Sleipner's rating. The listing prints 330 lb
  • Boat length 44 to 64 ft Sleipner's own range
  • Price per lb of thrust $14.74 Unit only. $35 to $60 installed
  • Voltage 24 V As sold
  • Battery at 24 V 1,064 CCA Two batteries, near the thruster
  • Run limit 2 to 3 min Duty cycle at 20 C ambient
  • To install it Haul-out The boat comes out of the water
  • Anodes $33.75 A change, at Defender

About the Sleipner SE150/215T-24V

The SE150 packs 400 lb of push into a 215 mm tube, making it a strong choice for boats of about 44 to 64 ft that can’t fit a wider tunnel. It is a 24 V, twin-propeller unit.

Defender sells it for $5,895. The tube, a control panel, a main switch and a fuse add about $775 to $1,448. It needs a 24 V supply from two batteries in series near the bow, and we put those batteries, the cable and charging at $1,146 to $1,451. See the parts list.

Read more

Give it short pushes, inside Sleipner’s rating of 2 to 3 minutes. Sleipner’s US distributor, Imtra, gets good marks from owners for support. The warranty is two years and transfers to the next owner.

The full spec sheet for a yard sits lower down, and the Sleipner (Side-Power) review covers Sleipner’s whole range.

Sleipner sold its thrusters under the Side-Power name until 2021, and many dealers and owners still call them that. It is the same company and the same thrusters.

Where this summary comes from (5 sources, read 12 October 2026)

Will the Sleipner SE150/215T-24V steer your boat?

70 FT TRAWLER · BOW · 15 KT WIND

Size forThis page always opens on Steering.

Every knot figure here is wind speed, not boat speed or current.

Steers her at 17 kt

On a 70 ft trawler the Sleipner SE150/215T-24V (400 lb) steers her in a 17 knot breeze. Her bow needs about 328 lb from a tunnel to steer her in a 15 knot breeze.

The finder lists it for her.

24.5 FT LEVER SE150/215T-24V pivot

A tunnel at the bow of a 70 ft trawler 328 lb ★ this unit · 1 to 3: the three cheapest others that steer her at 13 kt or more, installed

  1. ★ Sleipner SE150/215T-24V this unit 400 lb · tunnel from $14,266 Steers her at 17 kt
  2. 1 Max Power CT165 408 lb · tunnel from $12,458 Steers her at 17 kt
  3. 2 Lewmar 250TT GEN 2 Tunnel Thruster 308 lb · tunnel from $13,053 Steers her at 15 kt
  4. 3 Max Power CT225 (composite leg) 551 lb · tunnel from $13,097 Steers her at 19 kt

The Sleipner SE150/215T-24V on a trawler, by length

  1. 25 ft46 kt
  2. 30 ft39 kt
  3. 35 ft33 kt
  4. 40 ft29 kt
  5. 45 ft26 kt
  6. 50 ft23 kt
  7. 55 ft21 kt
  8. 60 ft19 kt
  9. 65 ft18 kt
  10. 70 ft17 kt
  11. 75 ft15 kt
  12. 80 ft15 kt

Outlined: the finder does not list it at that length (under 13 kt, far more than she needs, or outside Sleipner’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?

What Sleipner says 44 to 64 ft The maker's own range, from its listing
What our sizing says 60 to 70 ft Full thrust in 15 knots, across the kinds of boat it fits
Every kind of boat it fits, by length ten boat types
Which boats it fits, by length
Boat Full thrust at 15 knotsStill 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 56 to 70 ft None
Houseboat 42 to 60 ft 61 to 68 ftfull thrust to about 13 knots at 68 ft
Catamaran 63 to 70 ft None
Trawler 55 to 70 ft None
Motor yacht 55 to 70 ft None
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 No length. More thrust than the boat needs.
Center console No length. More thrust than the boat needs.

The Sleipner SE150/215T-24V 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 houseboat gets full thrust to 60 ft, and a sailboat to 70 ft. The maker gives one range for every boat.

The table tries the Sleipner SE150/215T-24V 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 down to 42 ft and up to 70 ft, just past Sleipner’s own range (44 to 64 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.

Installed by a yard
Boat Total installed
42 ft $13,686 to $20,544$34 to $51 a lb of thrust
55 ft $14,016 to $24,044$35 to $60 a lb of thrust
70 ft $14,266 to $24,774$36 to $62 a lb of thrust

From the shortest to the longest boat it is sized for.

What is in each total five lines

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 $750 to $3,380 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.

Each line of the estimate
Boat length The unit Yard labor Haul-out Batteries, cable, charger Other parts
42 ft $5,895 $5,120 to $9,72032 to 54 hours $750 to $2,030 $1,146 to $1,451 $775 to $1,448
55 ft $5,895 $5,120 to $12,60032 to 70 hours $1,080 to $2,650 $1,146 to $1,451 $775 to $1,448
70 ft $5,895 $5,120 to $12,60032 to 70 hours $1,330 to $3,380 $1,146 to $1,451 $775 to $1,448

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 24 V: two 12 V batteries in series, at least 1,064 CCA each (Sleipner’s minimum), $886 to $1,104 for both; Sleipner’s cable table gives 2/0 AWG: $114 to $201 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 2 of 5: Wiring prep only. The yard installs the unit and does the hull work; you do the wiring prep.

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 DIY

You: 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 three steps
  1. 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.
  2. 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.
  3. 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

Two of Sleipner’s own videos, from its YouTube channel. They play only when you tap. A maker’s video is its pitch, so take any claim back to the figures on this page.

Sleipner / Side-Power thruster systems - the importance of correct tunnel installation!Maker Sleipner’s own channel
eVision: Sleipner e-series thrustersMaker Sleipner’s own channel

Know before you buy

What sets this model apart, what it costs to keep, and what to weigh.

Price per pound of thrust

$14.74 a lb The unit’s price over its published thrust. The bars are Sleipner’s next sizes and the nearest other makers.

Controls

Gasket, bolts and anode with the unit. The panel, its cable, the fuse and main switch are bought.

Anodes

$33.75 a change

They sit below the waterline, so a change means a haul-out or a diver.

Service and warranty

Sleipner gives 2 years for leisure use and 1 for commercial use. It transfers to the next owner, and it starts no later than 18 months after the boat's first launch.

See Sleipner’s warranty Sleipner's warranty statement, effective 1 April 2022.

Special mentions

Battery: at 24 V it wants two batteries of 1,064 CCA or more, Sleipner's figure. The cheapest that meets it is the Dyno Group 8D heavy duty marine starting (flooded), $443.02. A sealed one is the Lifeline GPL-3100HC Group 31 AGM starting, $551.95. Check your own bank.

Charger: a NOCO GEN5X2 two-bank shore charger, $146.41. It is the one our estimate prices.

Sleipner 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: Sleipner rates the motor for 2 to 3 min at a stretch.

Parts for the Sleipner SE150/215T-24V

See the Sleipner SE150/215T-24V manual

The US dealer number comes first, then Sleipner’s own. 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

11 parts

The manual button above opens it on the maker's product page. It has the hull, wiring and fuse figures for this model.

From Sleipner’s SE80 to SE150 installation guide, document 2687 rev 30, 2025, read 25 October 2026.

In the box
The guide prints no box list. It has you install the unit with the gasket and the bolts provided.
Bought separately
The ANL fuse and a main switch ("must include"), the control panel with its own guide, the panel cable, the tunnel and the cable. Imtra, Sleipner's US distributor, lists the same items to buy with a new thruster.
Charging
The word "charging" is not in any of the Sleipner guides we read. The battery is sized by cold cranking amps, and a battery near the thruster is suggested. How it gets charged is left to you and your installer.

The manual’s words, page 19: “For installations on large vessels with bow and stern thrusters or catamarans a dedicated battery for each thruster should be considered.”

The “other parts” line in the estimate above covers these parts as a range, $775 to $1,448 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 “Sleipner fiberglass tunnel tube, 215 mm bore, 1000 mm”.

Sold in lengths from about 39 to 59 in. This is the shortest: the yard cuts the tube to the width of your hull at the thruster.

Part number SM12010

Control panel

Fisheries Supply lists it as “Side-Power 8950 G touch panel, one thruster”.

Part number SM8950G

Control cable, panel to thruster

Fisheries Supply lists it as “Side-Power 4-lead control cable, 4 m”.

Sold in lengths from 4 to 22 m. This is the shortest: measure the run from the helm to the thruster and buy the length that reaches.

Part number SM61277-04M

Main fuse

Fisheries Supply lists it as “Side-Power ANL fuse 500 A”.

The maker's figure: ANL 500.

Part number SMANL500

Fuse holder

Fisheries Supply lists it as “ANL fuse block, 35 to 750 A, cable up to 4/0, with cover”.

Part number 3903

Battery switch

Fisheries Supply lists it as “HD-Series 600 A battery switch, on/off”.

Rated at or above the 500 A main fuse. If your manual names its own switch, use that one.

Part number 3000

Control-circuit fuse holder

Fisheries Supply lists it as “Waterproof in-line ATO/ATC fuse holder”.

Your manual names no value for this: size a small in-line fuse to the wire.

Part number 5065

Batteries

Fisheries Supply lists it as “Dyno Group 8D heavy duty marine starting (flooded)”.

You need 2, each at 1,064 CCA or more, in series for 24 V. The cheapest listing that meets it.

Part number DNO 8DC

Battery cable, red and black

Defender lists it as “Ancor tinned battery cable 2/0 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.

Part number None on the listing. Order it by name.

Cable lugs

Fisheries Supply lists it as “Tin-plated starter lugs, 2/0 AWG, bag of 10”.

The listing runs $27.96 to $29.36 by stud size. Eight ends on one run, with two spare.

Part number 91066-P10

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.

Part number GEN5X2

Outside the hull replacement parts in the water

4 parts

Anode (250 and 300 mm gear leg)

The metal that wears away in the water so the drive does not. Sleipner calls it “Anode kit, aluminium aloy (Al-Zn-In)”.

Part number SM201180A Sleipner 201180A
See it at Defender$33.75 Price read 29 Oct 2026

Propeller

The propeller on the drive. Sleipner calls it “Propeller SE120/150 5bl Q-Prop™”.

Two per thruster. Sleipner lists it on the gear leg parts page for these models.

Part number SM91261 Sleipner 91261
See it at Defender$166.50 Price read 29 Oct 2026

Gear leg gasket

The leg under the motor that turns the propeller. Sleipner calls it “Gasket for gearleg/tunnel SE120/150”.

Sleipner lists it on the gear leg parts page for these models.

Part number 91355
See it at Sleipner No US price found

Gear leg, with propellers

The leg under the motor that turns the propeller. Sleipner calls it “Gearleg SE120/150”.

Part number 100600
See it at Sleipner No US price found

Inside the boat replacement parts on board

8 parts

Motor brush kit

Carbon brushes inside the motor. They wear down with use. Sleipner calls it “Brush kit SP155 + SE150/170”.

Sleipner asks for the thruster's serial number with every brush kit order. More than one kit is in print for this model, and the serial number decides which.

Part number BRUSH-14K
See it at Sleipner No US price found

Controller (the relay box on the motor)

A small switch in the motor’s control circuit. Sleipner calls it “Controller SE100-130 12V + SE150-250 24V”.

On the SE100 it is listed for the 12 V motor only.

Part number SM159147
See it at Sleipner No US price found

Solenoid (the motor switch)

The heavy switch that sends battery power to the motor. Sleipner calls it “Solenoid SE150/170/210/250/300”.

Listed on the motor pages for these models.

Part number 1013702
See it at Sleipner No US price found

Main fuse

The main fuse at the battery, in the rating the maker gives. Sleipner calls it “Recommended fuse A”.

The rating on Sleipner's product page for this model.

Part number ANL500
See it at Sleipner No US price found

Control panel, on/off dual joystick (bow and stern)

The control at the helm. Sleipner calls it “Dual joystick, 12/24 V”.

Runs a bow and a stern thruster.

Part number SM8940G Sleipner 8940G

Control panel, on/off single joystick

The control at the helm. Sleipner calls it “Single joystick, 12/24 V”.

For one on/off thruster.

Part number SM8960G Sleipner 8960G

Control panel, on/off touch panel

The control at the helm. Sleipner calls it “Touch panel, 12/24 V, 5-wire, round cut-out”.

For one on/off thruster.

Part number SM8950G Sleipner 8950G

Replacement motor

The electric motor that turns the propeller. Sleipner calls it “Electric motor SE150 24V”.

Part number 9010324
See it at Sleipner No US price found

The install parts are matched to Sleipner’s own figures and priced at Fisheries Supply, with the battery cable at Defender, cut to length.

Spare part numbers come from Sleipner’s parts pages and manuals. A dealer may sell a part we have not priced. Search for the number.

Other sizes and close alternatives

Compare them side by side

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, motor, mounting, price, part number, documents
Full spec sheet
Thrust and motor
Thrust 400 lb (181 kgf) As printed: Thrust @21VDC: 330 lbs (150 kg); Thrust @24VDC: 400 lbs (182 kg)
Thrust under load330 lb at 21 V
Motor8.8 kW
Voltage24 V
Run limit2 to 3 min duty cycle at 20 C ambient
Installation
TypeTunnel, fixed mount
End of the boatBow or stern
Tunnel diameter215 mm
What it does to the hullTunnel bore below the waterline
Haul-out to install itYes
Maker’s boat length44 to 64 ft
Price and ordering
Price $5,895 equipment only, a dealer's price, defender.com, 26 October 2026
Part number 88344124 V
Documents
Manual Installation manualon the maker's product page
The site’s reviewSleipner (Side-Power) review

Every published figure the site holds for the Sleipner SE150/215T-24V, with where each came from.

Draw, cable, fuse and battery at each voltage 24 V

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.

Draw, cable, fuse and battery
Voltage Draw Maker’s cable Fuse Battery Run limit
24 V 610 Anominal draw 2/0 AWG for up to 22 ft of cable counted out and back. Longer runs take heavier cableinstallation guide ANL 500installation guide 560 CCA DIN minimumSleipner installation manual, SE150/215T 2 to 3 min duty cycle at 20 C ambientproduct page, "Motor cycle duty"

The Sleipner SE150/215T-24V’s draw, cable, fuse, battery and run limit, as the maker publishes them.

The tunnel: length and depth rules

Tunnel length. Avoid a tunnel longer than four times its diameter. Friction inside a long tube slows the water and cuts thrust. Too short, and the flow reaches the propeller before it has straightened, which the manual says causes cavitation and noise. The propeller must sit entirely inside the tube. Sleipner’s installation manual.

Depth below the waterline. As deep as possible under the waterline, and as far forward as possible. The depth for a given model is in that model’s own measurements. Deeper prevents air being sucked in from the surface and raises the water pressure at the propeller. SE20 to SE40 installation guide, 5611 rev 25 (2025).

Our notes from the manual and listings

In the box: Gasket, bolts and anode with the unit. The panel, its cable, the fuse and main switch are bought.

Our note

Twin props in a 215 mm tunnel, 24 V only, for boats of 44 to 64 ft. It is rated 182 kg at 24 V and 150 at 21. The current guide (2687 rev 30) gives 610 A and a minimum battery of 560 cold cranking amps DIN (1,064 SAE).

The 2015 copy said 500 DIN, with 2/0 AWG cable to 7 m of total run and paired 3/0 from 22 m. The page rates the brushed motor for two to three minutes' running at 20 C. The control panel switches itself off after about six minutes unused. Sleipner's FAQ wants the tunnel at least three quarters of its diameter below the surface, never less than half.

Where each point above comes from
  • Sleipner sells it for either end, so it can go at the bow or the stern.The maker's listing
  • Sleipner also prints a second, lower thrust figure for when the battery sags under load: 330 lb at 21 V.The maker's published rating
  • 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.

Where to go next

The specs are the maker’s and the dealers’, on the dates shown. The sizing and the costs are our arithmetic, done without seeing your boat.