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Sideshift · external thruster · stern
Sideshift ST350-D: specs, price and the boats it fits
Sideshift prints no thrust figure for it. Sideshift sells it for boats of 50 to 70 ft. It runs on 24 V.
- Goes on afloat
- DIY 4 of 5: you install it, electrician connects
- 2-year warranty
Quick stats
- Thrust Not published Our sizing works from the motor's rating
- Boat length 50 to 70 ft Sideshift's own range
- Price per lb of thrust Not worked out It needs a price and a thrust figure
- Voltage 24 V As sold
- Battery at 24 V 850 CCA Two batteries, near the thruster
- Run limit Bursts of 3 to 5 seconds Never more than 20 to 30 seconds at a time
- To install it Afloat The maker says it goes on in the water
- Anodes $30.00 A change, at Sideshift
About the Sideshift ST350-D
The ST350-D gives a big boat strong steering at the stern: two complete ST350 stern thrusters, one on each side of the transom, run from one joystick. It’s made for boats of 50 to 70 ft and up to 35 tons. Each half is a full ST350, the Sideshift stern unit with the longest owner record.
Bought as two single ST350 kits, the pair would cost $10,990. The ST350-D is $8,995, which saves you $1,995, and you get one joystick to steer both. Each unit still comes with its own controller and battery switch, so plan on two full installs.
Read more
What isn’t in the box is the batteries, because each unit runs on its own 24 V bank. Sideshift’s manual and its FAQ give different battery sizes for this kit, so ask Sideshift to confirm before you buy them. With cable and charging, figure about $1,961 to $2,136 more.
Owners have reported on the ST350 since 2012, and most are happy with it. The complaints that come back are shaft seals failing at around seven years and lines catching on the units. Each push is full on or off. Sideshift’s habit is 3 to 5 seconds, and its ceiling is 20 to 30. A replacement motor is $1,595 per unit, and the warranty is two years on parts.
The full spec sheet for a yard sits lower down, and the Sideshift thruster review covers Sideshift’s whole range.
Where this summary comes from (6 sources, read 11 October 2026)
Is it right for your boat?
Every kind of boat it fits, by length
| Boat | Lengths it fits, on our estimate |
|---|---|
| Pontoon & tritoon | Not listed. Its maker does not name this kind of hull. |
| Sailboat | 45 to 77 ft |
| Houseboat | Not listed. Its maker does not name this kind of hull. |
| Catamaran | Not listed. An external unit bolts to the side of a single hull at the bow or to its transom, and a cat has two narrow hulls with a bridgedeck between them, so there is nowhere forward to hang one. |
| Trawler | 45 to 77 ft |
| Motor yacht | 45 to 77 ft |
| Bass & flats | No length. Outside the maker's length range. |
| Wake & ski boats | No length. Outside the maker's length range. |
| Express cruiser | 45 to 65 ft |
| Center console | No length. Outside the maker's length range. |
The Sideshift ST350-D Stern Thruster against each kind of boat, in a 15 knot wind. Our sizing, from the finder’s own rules.
How we size it
Sideshift prints no thrust, so our sizing uses an estimate from the motor’s rating. That estimate can say a boat is too big for it. It cannot promise a fit. The maker gives one range for every boat.
The table tries the Sideshift ST350-D Stern Thruster 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 where it mounts 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 45 ft and up to 77 ft, just past Sideshift’s own range (50 to 70 ft).
It is sized for four 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 |
|---|---|
| 45 to 77 ft | $13,524 to $18,343 |
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. 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 | Batteries, cable, charger | Other parts |
|---|---|---|---|---|
| 45 to 77 ft | $8,995 | $2,560 to $7,20016 to 40 hours | $1,961 to $2,136 | $8 to $12 |
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 for each of the two thrusters: two 12 V batteries in series, at least 850 CCA each (Sideshift’s minimum), $1,440 for all four; Sideshift’s cable table gives 2/0 AWG (its table stops short of 20 ft, so keep the battery closer): $228 to $403 for the red and black cable and the lugs; two GEN5X2 chargers, $293.
Installing it yourself. Tell the finder you will fit a Sideshift yourself and it takes the yard’s labor off. With that off, the total is $10,964 to $11,143. That is the unit plus the batteries, cable and other parts, which you buy whoever does the installing.
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: 16 to 40 hours Yard: none Electrician: 4 to 8 hours No haul-out.
Your part needs:Drilling above the waterlineHeavy battery cableCrimping big lugs
Every step, and who does it
- Mount the thruster; fit the battery, controller and joystick; run the cables You 8 to 20 hours each unit Our arithmetic, worked back from Sideshift’s own published installed range of $5,750 to $9,400 against its kit prices. Treat it as a rough size, not a quote. Every mount and connection is above the waterline.
- Final connections at the battery and the motor, load test Electrician 2 to 4 hours each unit 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 from Sideshift’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
Sideshift prints no thrust, so there is nothing to divide the price by.
Controls
Two thrusters in the kit, one for each end. The kit has the thruster, the controller, the wireless joystick and key fob, the harness, the fuse and a battery switch. You buy the batteries, the cable and a charger. The joystick is wireless but needs 12 V at the helm for its own power.
- Wireless remote (key fob) (KF-U), no US price found.
Anodes
$30.00 a change- Anode kit (AK-S-2): $30.00 at Sideshift.
Service and warranty
Sideshift gives 2 years against faulty workmanship or materials. Its exclusions include wrong wire size or low voltage, burn-out from overuse, collisions, and tangled line or netting.
See Sideshift’s warranty Installation manual, Rev 3.1, p. 68.Special mentions
Battery: at 24 V it wants two batteries of 850 CCA or more, Sideshift's figure. The cheapest that meets it is the Optima BlueTop SC27DM Group 27 AGM, $359.99. Check your own bank.
Charger: a NOCO GEN5X2 two-bank shore charger, $146.41. It is the one our estimate prices.
Dealer prices at Fisheries Supply, read 26 October 2026.What to weigh
Sideshift publishes no thrust figure for it. The boat table uses our estimate from the motor's rating.
It runs in bursts of 3 to 5 seconds, never more than 20 to 30 seconds at a time.
Short pushes only: Sideshift rates the motor for bursts of 3 to 5 seconds at a stretch.
Parts for the Sideshift ST350-D Stern Thruster
See the Sideshift ST350-D 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 on the maker's site. It has the hull, wiring and fuse figures for this model.
From Sideshift’s Monohull installation manual Rev 3.1, November 2025, read 30 September 2026.
- In the box
- The thruster, the motor controller, the wireless joystick and its receiver, a wireless key fob, the wiring harness and mounting hardware, the fuse in a holder with a digital voltage display, and a battery switch. Sideshift lists these on each product page. The manual adds the crimper, anti-seize, Loctite, Sikaflex and heat shrink.
- Bought separately
- The batteries, the 1/0 or 2/0 battery cable and the charger. The joystick is wireless: no wire runs from it to the thruster. It still needs 12 V at the helm for its own power, so plan a small feed there.
- Charging
- The thruster gets a bank of its own: cranking type, 850 cold cranking amps per battery, within 10 ft of the controller. You buy the charger too, either a shore charger or a DC-to-DC charger fed off the bank the alternator charges.
The manual’s words, page 40: “The 2 most popular ways are: AC/DC multi-bank charger such as the NOCO GEN5X2 (available in our online store). ... Using a DC-DC Isolated Charger such as the Victron Orion-Tr DC-DC Converters Isolated.”
The “other parts” line in the estimate above covers these parts as a range, $8 to $12 at Fisheries Supply’s prices on 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.
Control-circuit fuse holder
Fisheries Supply lists it as “Waterproof in-line ATO/ATC fuse holder”.
Sideshift names no fuse for the joystick's 12 V feed at the helm (its receiver has its own 10 A fuse): size a small in-line fuse to the wire.
Batteries
Fisheries Supply lists it as “Optima BlueTop SC27DM Group 27 AGM”.
You need 4, each at 850 CCA or more, 2 for each thruster, in series for 24 V. The cheapest listing that meets it. Two banks, one for each thruster: the maker wires each unit on its own.
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 each thruster. 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. Sideshift's manual: "Ensure the total cable run from the battery to the motor controller does not exceed 10 ft (3 m)."
Cable lugs
Fisheries Supply lists it as “Tin-plated starter lugs, 2/0 AWG, bag of 10”.
You need 2 bags. The listing runs $27.96 to $29.36 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”.
You need 2. Or a DC-to-DC charger from the house system: ask the electrician.
Transom bracket
Ask for Sideshift transom mount bracket EX1-11 (L-shaped).
The manual calls it the preferred mount for most inboard boats; Sideshift sells it separately.
Extension bracket, if needed
Ask for Sideshift 5, 10 or 15 in stern extension bracket (EX1-12, EX1-10, EX1-13).
Only where the swim platform sits 3 to 18 in above the waterline (the manual's table).
Outside the hull replacement parts in the water
Anode kit
The metal that wears away in the water so the drive does not. Sideshift calls it “Single/Dual Propeller Anode Kit (AK-S-2)”.
Sideshift says this kit fits all Sideshift thrusters. The manual says replace the anodes at least once a year.
Replacement motor, Pearl White
The electric motor that turns the propeller. Sideshift calls it “SS350 / ST350 / HB350 Replacement Motor Kit”. This one is for the Pearl White finish version.
Sideshift says it fits all 350 series thrusters. Includes mounting hardware and an anode kit; no propeller. Sold for repair of existing Sideshift systems only. A two-unit system has two motors; this kit replaces one.
Replacement motor, Phantom Black
The electric motor that turns the propeller. Sideshift calls it “SS350 / ST350 / HB350 Replacement Motor Kit”. This one is for the Phantom Black finish version.
Sideshift says it fits all 350 series thrusters. Includes mounting hardware and an anode kit; no propeller. Sold for repair of existing Sideshift systems only. A two-unit system has two motors; this kit replaces one.
Inside the boat replacement parts on board
Wireless remote (key fob)
The handheld control. Sideshift calls it “Wireless Remote Key Fob”.
Sideshift says it works with all Sideshift thruster systems. The store shows "Call for price". The manual says it takes a CR2032 coin cell.
No part matches. Try the number without spaces, or the part’s name.
The install parts are matched to Sideshift’s own figures and priced at Fisheries Supply, with the battery cable at Defender, cut to length.
Spare part numbers come from Sideshift’s parts pages and manuals. A dealer may sell a part we have not priced. Search for the number.
Other sizes and close alternatives
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 | Not published |
| Motor | 11.19 kW |
| Voltage | 24 V |
| Run limit | bursts of 3 to 5 seconds, never more than 20 to 30 seconds at a time |
| Installation | |
| Type | External, fixed mount |
| End of the boat | Stern |
| What it does to the hull | Three small holes, all above the waterline |
| Haul-out to install it | No: the maker says it goes on afloat |
| Maker’s boat length | 50 to 70 ft |
| Price and ordering | |
| Price | $8,995 full kit, the maker's own price, sideshift.com, 26 October 2026 |
| Part number | Not held for this listing |
| Documents | |
| Manual | Installation manual (PDF)on the maker's site |
| The site’s review | Sideshift thruster review |
Every published figure the site holds for the Sideshift ST350-D Stern Thruster, 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 |
|---|---|---|---|---|---|
| 24 VEach of the two thrusters | 400 Astart current | 2/0 AWG, for up to 10 ft of cable counted out and backinstallation manual, Rev 3.1 | Not published | Each thruster is wired on its own, to its own two 12 V starting batteries of at least 850 CCA each, in series for 24 Vinstallation manual, Rev 3.1, p. 30 | bursts of 3 to 5 seconds, never more than 20 to 30 seconds at a timeinstallation manual, Rev 3.1 |
The Sideshift ST350-D Stern Thruster’s draw, cable, fuse, battery and run limit, as the maker publishes them.
- At 24 V: size the cable for your run, or check the battery you have.
Our notes from the manual and listings
In the box: Two thrusters in the kit, one for each end. The kit has the thruster, the controller, the wireless joystick and key fob, the harness, the fuse and a battery switch. You buy the batteries, the cable and a charger. The joystick is wireless but needs 12 V at the helm for its own power.
Our note
Two ST350 units, one each side of the transom, on one control. Sideshift rates the pair for boats to 35 tons, and it goes on with the boat afloat. The manual's battery line for this kit reads 850 cold cranking amps each, where the FAQ says 850 in total. Ask which before you buy batteries.
Bursts only: the manual asks for pushes of 3 to 5 seconds as normal practice, and never more than 20 to 30 seconds at a time. Its warranty does not cover a motor burned out by overuse. On 17 September 2026 sideshift.com was running an end of summer sale, with ten percent off every thruster. The price here is the list price. The sale was still on when the page was read again on 2 October 2026.
Where each point above comes from
- It goes on with the boat in the water. No haul-out is needed to install it.Sideshift: "All Sideshift thrusters can be installed in-water since all the mounting locations and cable connections are routed above the waterline."
- Sideshift publishes no thrust figure for it. The boat table uses our estimate from the motor's rating.The maker's published specs
- It runs in bursts of 3 to 5 seconds, never more than 20 to 30 seconds at a time.installation manual, Rev 3.1
Not sure this is the one? The thruster finder asks about your boat and prices every unit that fits.