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Thruster specs
Max Power CT35-IP: specs, price and the boats it fits
The CT35-IP brings Max Power’s smallest tunnel thruster to boats with gasoline engines, about 17 to 34 ft. A sealed housing around the motor, relay and wiring keeps fuel fumes away from any spark. Push is 77 lb on 12 V from a single propeller in a 125 mm tube.
Marinedeal sells it for $2,456, the same as WMJ Marine, against $1,276 for the standard CT35: the sealing is what the difference buys. Add about $473 to $1,024 for the tube, a panel, a main switch and a fuse, and about $601 to $820 for one starting battery near the bow, its cable and a charger. See the parts.
The manual rules out lithium: lead-acid only. The sealed composite leg means no zinc to change. Keep each push under 2 to 3 minutes. Warranty: two years, extendable to three.
Fitting it yourself? The installer section has every spec, and the Max Power thruster review sets this model against the rest of the Max Power range.
Where this summary comes from (5 sources, read 12 October 2026)
Key facts
- DIY level 2 of 5 Wiring prep only
- Thrust 77 lb 35 kgf, Max Power's rating
- Boat length 17 to 34 ft Max Power's product page
- Price $2,456 equipment only, marinedeal.com, 12 October 2026
- Fitted by a yard $9,360 to $14,870 Our estimate at 40 ft, unit and job
- Voltage 12 V As sold
- Mounts Tunnel Fixed mount, end not stated
- To fit it Haul-out The boat comes out of the water
- Run limit 2 to 3 min At a stretch, depending on the air temperature. The motor's S2 rating is 3 min
Every figure here is the maker’s or a dealer’s, except the fitted cost, which is our 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. Here a sailboat gets full thrust to 29 ft, and a center console to 40 ft.
The table below tries the Max Power CT35-IP 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. The listing prints no boat length, so thrust alone decides. Max Power's own figures are in the opening lines.
| 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 | 25 to 29 ft | 30 to 44 ftfull thrust to about 10 knots at 44 ft |
| Houseboat | None | 30 to 33 ftfull thrust to about 10 knots at 33 ft |
| Catamaran | 30 to 33 ft | 34 to 50 ftfull thrust to about 10 knots at 50 ft |
| Trawler | 25 to 29 ft | 30 to 44 ftfull thrust to about 10 knots at 44 ft |
| Motor yacht | None | 35 to 44 ftfull thrust to about 10 knots at 44 ft |
| 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 | 32 to 37 ft | 38 to 56 ftfull thrust to about 10 knots at 56 ft |
| Center console | 35 to 40 ft | None |
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 seven kinds 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
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 $450 to $2,700 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. Your own yard will have its own opinion. The cost page builds the same figures line by line.
| Boat length | The unit | Yard labor | Haul-out | Batteries, cable, charger | Other parts | Total |
|---|---|---|---|---|---|---|
| 25 ft | $2,456 | $5,120 to $5,760about 32 hours | $450 to $1,210 | $601 to $820 | $473 to $1,024 | $9,100 to $11,270 |
| 40 ft | $2,456 | $5,120 to $8,64032 to 48 hours | $710 to $1,930 | $601 to $820 | $473 to $1,024 | $9,360 to $14,870 |
| 56 ft | $2,456 | $5,120 to $12,60032 to 70 hours | $1,090 to $2,700 | $601 to $820 | $473 to $1,024 | $9,740 to $19,600 |
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 12 October 2026.
- At 12 V: one 12 V battery, at least 800 CCA (Max Power’s minimum), $360 for the battery; Max Power’s cable table gives 1/0 to 3/0 AWG, priced on 1/0 to 4/0 AWG, the nearest size cut to length: $95 to $314 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.
What else you buy
What follows comes from Max Power’s CT100 and CT125 installation manual, July 2024, read 30 September 2026.
- In the box
- The motor with its relay, the electronic controller, the composite leg with screws and gasket, two propellers. "The thruster is delivered without accessories (fuse, fuse holder, control panel)."
- Bought separately
- The fuse and holder, a manual battery isolator and an electric one, the control panel, an 8 A control fuse, a breaker on the DC panel, the cable, the tunnel. No anode on the composite leg.
- Charging
- Max Power is the one maker that asks for both: the engine's alternator and a charger. A dedicated bank is optional and goes "as close as possible to the thruster". It wants starting-type batteries with high cold cranking amps.
The manual’s words, page 3: “The batteries used by the thruster must be charged by both the main engine's alternator and an appropriate battery charger.”
The “other parts” line in the estimate above is the priced parts below, $473 to $1,024 at Fisheries Supply’s prices on 30 September 2026. The batteries, cable and charger have a line of their own.
| 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. | Max Power names none | $136–$209125 mm fiberglass tunnel tubes up to 60 in (1.5 m) long (Sleipner Side-Power), at Fisheries Supply, read 16 October 2026. |
| Control panel | The buttons or joystick at the helm. One helm, one panel: a second steering station needs a panel of its own. | A Max Power control panel, sold with its own guide | $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. | Max Power names none | $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. | Ceramic or ANL, the rating in the manual's table | $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. | Holder T1 OPTI3119 or T2 | $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. | A manual isolator, plus the electric isolator OPTI3160/3 (12 V) or OPTI3170/3 (24 V) | $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. | An 8 A fuse on the control box feed | $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. | Max Power 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. | Max Power 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. | Max Power 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. | Max Power 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 | 77 lb (35 kgf) As printed: 35 / 77 (kg/lbs) |
| Motor | 2.69 kW |
| Voltage | 12 V |
| Fitting | |
| Type | Tunnel, fixed mount |
| End of the boat | Not stated |
| Tunnel diameter | 125 mm |
| What it does to the hull | Tunnel bore below the waterline |
| Haul-out to fit it | Yes |
| Maker’s boat length | 17 to 34 ftMax Power's product page; the listing prints none |
| The tunnel | |
| Depth below the waterline | The minimum acceptable position is 139 mm below the waterline. Ideally the top of the installed tunnel sits 185 mm below it. Shallower than the ideal, the manual says, performance falls off progressively. CT100 and CT125 installation manual (July 2024) |
| Price and ordering | |
| Price | $2,456 equipment only, a dealer's price, marinedeal.com, 12 October 2026 |
| Part number | 317609Ignition-protected, mono propeller, 12 V |
| Documents | |
| Manual | Installation manual (PDF)on the maker's site |
| Warranty | Max Power's website gives 3 years. Its manual gives 2, and 1 more if the warranty is registered within 3 months of installation. Outside pleasure craft it is 6 months. It transfers to the next owner, and the first year covers up to 2 hours of labor in the field. Max Power's warranty conditions |
| The site’s review | Max Power thruster 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 |
|---|---|---|---|---|---|
| 12 V | 250 Ameasured draw | 1/0 AWG for up to 16 ft of cable counted out and back. Longer runs take heavier cableCT35-IP/CT45-IP installation manual | 125 ACT35-IP / CT45-IP manual | Maintenance-free "starting" type batteries, with high CCA outputs. The manual's example is the Exide Maxxima 900, 800 CCA and 55 AhMax Power installation manual CT35-IP / CT45-IP, February 2026 | 2 to 3 min at a stretch, depending on the air temperature. The motor's S2 rating is 3 minCT35-IP / CT45-IP manual |
- At 12 V: size the cable for your run, or check the battery you have.
What to weigh
Each point names the fact it rests on.
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
- Max Power's product page puts it on boats of 17 to 34 ft. Its selection chart puts it on 17 to 25 ft boats with heavy displacement and high windage, and out to 31 ft on light ones. The listing the price comes from prints no range. The boat table is our sizing alone.Max Power's product page and selection chart, read 15 September 2026
What the manual and listings say
This is the note we keep on the Max Power CT35-IP, written from the maker’s manual, its product pages and the dealer’s listing.
In the box: Delivered without accessories: the fuse, holder and control panel are bought.
Our note
The ignition-protected build, for a boat with gasoline engines or tanks in the same space. The same 35 kg unit as the CT35, but its page gives a band of 17 to 34 ft where the CT35's says 17 to 31. The CT35/CT45 manual measures 250 A at 11 V and fuses it at 125 A ceramic or 175 A ANL.
Standard on/off units are made for lead-acid, AGM or gel batteries. Max Power's FAQ says lithium will damage them unless specified correctly. Max Power publishes no price and sells through dealers. The figure here is a US dealer's listing for the unit alone.
Videos
One of Max Power’s own videos, from its YouTube channel: a short reel of the range. It is the maker’s pitch. Watch it 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
Max Power also sells this thrust built another way. Each has its own page:
- Not ignition-protected: Max Power CT35, $1,276.
These are Max Power’s nearest sizes by thrust, in any of its lines.
- One size down: Max Power CT25, 66 lb.
- One size up: Max Power CT45-IP, 88 lb, $2,456.
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.
- VETUS Bow 35, 77 lb, $1,786.
- Lewmar 125TT Tunnel Thruster, 77 lb, $1,846.
- Sleipner SE25/110S, 66 lb, $1,485.
Every model with a page here is listed, maker by maker, on the thruster index.