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Thruster specs
Sleipner E420 eVision: specs, price and the boats it fits
The E420 is the largest tunnel thruster on this site: 926 lb of push from counter-rotating twin propellers in a 386 mm tube, for yachts of about 69 to 113 ft. It is a 48 V eVision unit with speed control built in.
Not sold in the US right now. No US store or distributor lists the Sleipner E420 eVision: we checked Imtra’s US catalog (the Sleipner distributor), Defender and Fisheries Supply on October 15, 2026. Its specs and parts stay here for owners of boats built or bought abroad. For one to buy here, see the models on the Sleipner (Side-Power) review that have a US price.
Neither Sleipner nor a US dealer publishes a price; it is quoted through Sleipner’s dealers, Imtra in the US. Plan on about $1,189 to $2,130 for the tube, a joystick panel, a main switch and a fuse. Its 48 V bank of four large batteries, with cable and charging, comes to about $2,245 to $2,815 on our figures. See every part.
A tube this wide is a new-build or major refit decision, made with the yard and the designer. The motor follows the rest of the eVision line: no carbon brushes, active air cooling and full thrust rated continuous at 22 C, limited by battery capacity. Warranty: two years for leisure use, transferable.
Installers will find the wiring figures and dimensions further down. For the rest of Sleipner’s line, read the Sleipner (Side-Power) review.
Where this summary comes from (5 sources, read 12 October 2026)
- Sleipner product page
- Sleipner E420 eVision installation manual, document 8075 rev 4
- Imtra, Sleipner’s US distributor: SE60 12 V listing
- Imtra, "Sleipner’s eVision Thrusters: Setting the Standard in Performance & Efficiency" (brushless, no carbon brushes; run time limited by the batteries; less heat; proportional as standard)
- Sleipner warranty statement, effective 1 April 2022
Key facts
- DIY level 2 of 5 Wiring prep only
- Thrust 926 lb 420 kgf, Sleipner's rating
- Boat length 69 to 113 ft Sleipner's own range
- Price No US price None is published, so there is no fitted cost to work out
- Fitted by a yard No total No price to build on
- Voltage 48 V As sold
- Mounts Tunnel Fixed mount, bow or stern
- To fit it Haul-out The boat comes out of the water
- Run limit Not published Ask the maker before long use
Every figure here is the maker’s or a dealer’s. No US price is published, so there is no fitted cost to estimate. The full spec sheet is further down.
How much of the install is yours
DIY levels
- 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.
You Yard Electrician. The bar is labor hours; a haul-out is a note.
How we rate DIYYou: 4 to 16 h Yard: 32 to 70 h Electrician: 2 to 4 h Plus a haul-out.
- Cut, bond and fair the tunnel; fit the gear leg, motor and propeller Yard 32 to 70 h 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 h 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 h Our estimate. Nobody publishes a time for the final connections and test on their own.
Your part needs:Heavy battery cableCrimping big lugs
A qualified marine electrician should make the final connections and test them before first use. Hours are labor only.
Is it right for your boat?
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. The maker gives one range for every boat.
The table below tries the Sleipner E420 eVision 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 63 ft, just past Sleipner’s own range (69 to 113 ft).
| 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 | No length. More thrust than the boat needs. | |
| Houseboat | 63 to 76 ft | 77 to 80 ftfull thrust to about 14 knots at 80 ft |
| Catamaran | No length. More thrust than the boat needs. | |
| Trawler | No length. More thrust than the boat needs. | |
| Motor yacht | No length. More thrust than the boat needs. | |
| 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. | |
Reading the two length columns. 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 falls short of what the boat needs by no more than 10 percent, and gives the whole figure only in the lighter wind named. On a boat shorter than the first column’s shortest length, the unit is more than the boat needs.
It is sized for one kind of boat here. For your own boat, the finder gives an answer that also counts your drive and who does the fitting. The compare page sets this unit beside others.
What it costs fitted
No US dollar price is published for the Sleipner E420 eVision, so we build no total for it. The yard’s share of the job is on the cost page.
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.
What else you buy
What follows comes from Sleipner’s SE80 to SE150 installation guide, document 2687 rev 30, 2025, read 30 September 2026.
- In the box
- The gasket, bolts and anode come with the unit. The SEP guides call the power controller "the included PPC unit".
- 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.
- 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.”
A yard job adds these parts on top of the unit: $1,189 to $2,130 for the priced ones below, at Fisheries Supply’s prices on 30 September 2026, plus the batteries, cable and charger.
| Part | What it is | What to ask for | Dealer price |
|---|---|---|---|
| Tunnel tube | The fiberglass, aluminum or steel pipe the thruster sits in, bonded through the bow. | Sleipner names none | $852–$1,315300 mm fiberglass tunnel tubes up to 60 in (1.5 m) long (Sleipner Side-Power), at Fisheries Supply, read 16 October 2026. No dealer we read lists a 386 mm tube. This is the 300 mm price, the largest bore listed. |
| Control panel | The buttons or joystick at the helm. One helm, one panel: a second steering station needs a panel of its own. | SM8960G single joystick, SM8950G touch panel | $219–$374Side-Power touch panel and single joystick, VETUS push-button panel, Lewmar single joystick, at Fisheries Supply. |
| Control cable, panel to motor | The thin cable from the helm to the motor. Sold by length. | Side-Power 4-wire control cable, by length | $29–$173Side-Power control cables, VETUS panel cables, Lewmar Gen 2 connecting cables, at Fisheries Supply. |
| Main fuse | A slow-blow fuse of the ANL type at the battery, in the size the maker prints for the model. | Side-Power ANL fuse, the rating in the yard table below | $18–$57Side-Power ANL fuses, Blue Sea ANL fuses, at Fisheries Supply, read 16 October 2026. |
| Fuse holder | The block the ANL fuse bolts into, with a cover. | SMANLHOLD (SMANLHOLD-C with a cover) | $27–$93Egis and Blue Sea ANL fuse blocks, Side-Power ANL fuse holders, at Fisheries Supply, read 16 October 2026. |
| Main battery switch | The switch that cuts the thruster off from its battery when you leave the boat. | Side-Power manual main switch, 350 or 600 A, or the automatic AMS | $35–$107Egis m-Series 300 A, Blue Sea e-Series 350 A and HD-Series 600 A on/off switches, at Fisheries Supply, read 16 October 2026. |
| Control-circuit fuse and switch | A small fuse, and often a switch, on the thin wire that powers the panel or control box. | Sleipner names none | $8–$12Blue Sea in-line ATO fuse holders, at Fisheries Supply, read 16 October 2026. |
| Battery cable and lugs | The two heavy cables from the battery to the motor, sized to the length of the run. The wiring calculator sizes them. | Sleipner names none | In the electrical line |
| Battery bank | A cranking-type bank near the motor, sized by the maker's cold cranking amps. The battery calculator checks it. | Sleipner names none | In the electrical line |
| Charger or charge feed | How the thruster bank gets charged: a shore charger of its own, a DC-to-DC charger or charging relay from the boat's system, or a charger built into the unit. | Sleipner names none | $146–$305NOCO GEN5X2 shore charger, Victron Orion-Tr Smart DC-DC charger, Blue Sea ML-ACR charging relay, at Fisheries Supply. |
| Glass, resin, filler and sealant | What bonds the tube or housing into the hull and seals the gear leg. | Sleipner names none | Not priced |
The cost page has the whole list with what every maker says about each part.
For the yard and the installer
The full spec sheet, grouped the way a yard reads it. Every figure is the maker’s or a dealer’s, with its source.
| Thrust and motor | |
|---|---|
| Thrust | 926 lb (420 kgf) As printed: 420 kg / 926 lbs |
| Motor | 24.5 kW |
| Voltage | 48 V |
| Fitting | |
| Type | Tunnel, fixed mount |
| End of the boat | Bow or stern |
| Tunnel diameter | 386 mm |
| What it does to the hull | Tunnel bore below the waterline |
| Haul-out to fit it | Yes |
| Maker’s boat length | 69 to 113 ft |
| The tunnel | |
| 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) |
| Price and ordering | |
| Price | No US price published |
| Part number | E420/386TC-48V48 V, 48 V DC (nominal 42 V DC) |
| Documents | |
| Manual | Installation manualon the maker's product page |
| 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. Sleipner's warranty statement, effective 1 April 2022 |
| The site’s review | Sleipner (Side-Power) review |
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 |
|---|---|---|---|---|---|
| 48 V | 545 Anominal draw | 3/0 AWG for up to 22 ft of cable counted out and back. Longer runs take heavier cableinstallation guide | ANL 500installation guide | 545 CCA DIN minimumSleipner installation guide, E420 eVision, document 8075 rev 4 (2026) | Not published |
- At 48 V: size the cable for your run, or check the battery you have.
What holds up and what to weigh
Each point names the fact it rests on.
What holds up
- Sleipner sells it for either end, so it can go at the bow or the stern.The maker's listing
What to weigh
- The boat comes out of the water to fit it: it needs a tunnel bore below the waterline.The mounting: a bore through the hull, or a housing recessed into it
- No US dollar price is published for it, so we can work out no fitted cost.The maker and the dealers the database reads
What the manual and listings say
This is the note we keep on the Sleipner E420 eVision, written from the maker’s manual, its product pages and the dealer’s listing.
In the box: A brushless eVision motor on S-Link control. The panel, fuse and main switch are bought.
Our note
The brushless eVision motor comes from the series launched in 2022. The page rates it continuous at 22 C, limited only by the battery. The motor holds one thrust figure across the voltage range. The brushed series print a lower figure at the voltage a battery sags to. The largest tunnel unit on the site: twin counter-rotating props in a 386 mm tunnel, 24.5 kW, 48 V only.
The maker's page puts it on boats of 69 to 113 ft. Sleipner's FAQ wants the tunnel at least three quarters of its diameter below the surface, never less than half. There is no dealer price, and the maker publishes none.
Videos
Two of Sleipner’s own videos, from its YouTube channel: the current E-series tunnel units, and how the tunnel mouth changes the thrust you get. They are the maker’s pitch. Watch them for what the unit looks like and how it goes in, and take any claim back to the figures above.
Other sizes and close alternatives
These are Sleipner’s nearest sizes by thrust, in any of its lines.
- One size down: Sleipner E340 eVision, 750 lb, $15,250.
- One size up: Sleipner SAC450, 992 lb, $28,500.
These are other makers’ units of the same style, for the same end, within a quarter of its published thrust. Each is that maker’s nearest match.
- Max Power CT325 (24 V), 717 lb, $6,510.
Every model with a page here is listed, maker by maker, on the thruster index.