Product19 January 2026

Electric Boat Motors: Types, Power, and What to Look For

By Jason Rieck
Co-Founder & Lead Designer, Cat Cruisers

Electric boat motors have come a long way from the little trolling motors bolted to the back of fishing boats. Today they range from small units for tenders and dinghies to big systems for heavy cruisers. The trouble is the jargon: kW, horsepower, torque, outboard, inboard, pod. Here's what it all means, in plain English.

Three ways to fit a motor

Electric motors on boats come in three main layouts.

An outboard hangs off the back of the boat, just like a petrol outboard, with the motor and its controls in one unit. It's like carrying a backpack: easy to put on and take off. Electric outboards suit tenders, dinghies and small fishing boats.

An inboard sits inside the hull and turns a shaft that runs out to the propeller. It's more like your heart: tucked away inside and doing the heavy lifting. Inboards usually suit heavier boats and need professional installation.

A pod drive sits under the hull, with the motor, gears and propeller in one underwater unit. Think of it as a foot. Pods are popular on catamarans because each hull can have its own, and some can swivel to steer.

Cartoon of Jason in a white linen shirt and gold aviators posing on a jetty at a Queensland boat ramp with a backpack on his back, a glowing heart on his chest and coral swim flippers on his feet, while his co-host DJ, in a white crochet cropped cardigan, pink flared jeans and a denim star bag, laughs as she taps the heart — Outboard, inboard, pod: worn on the back, tucked inside, or down below. Fashion optional.

kW vs horsepower, without the maths headache

Electric motors are rated in kilowatts (kW). Petrol motors are usually rated in horsepower (hp). The straight conversion is simple: 1 kW is about 1.34 hp. So a 5 kW motor is about 6.7 hp, and a 10 kW motor is about 13.4 hp.

Cartoon of a horse and a smiling toaster balanced perfectly on an old brass scale with a blue rosette at an Australian country show, as DJ in a straw hat, white crochet cardigan and pink flared jeans explains with a raised finger and Jason peers over his sunglasses from a hay bale, holding hot chips — 1 kW ≈ 1.34 hp. The horse is not thrilled about the comparison.

On paper, those numbers look tiny next to the big outboards on many Aussie runabouts. But the raw number doesn't tell the whole story, for two reasons.

First, efficiency. A petrol engine loses a big chunk of its fuel's energy as heat and noise. An electric motor turns far more of its power into actually spinning the propeller. It's like carrying water up a hill in a leaky bucket versus a sound one: the sound bucket gets more water to the top.

Cartoon of Jason getting soaked by a bucket full of holes on a grassy farm hill with a windmill and water tank, while DJ in a white crochet cardigan and pink flared jeans strolls ahead with a full bucket and a kookaburra laughs — Same water, same hill. The leaky bucket is the petrol engine.

Second, torque. Torque is turning force, the "shove" that gets things moving. Electric motors deliver strong torque from a standstill, so they respond the moment you push the throttle. There's no warm-up and no lag. Picture a sprinter exploding off the blocks while an old diesel truck is still coughing into life.

Cartoon of DJ in a white crochet cardigan, pink flared jeans and platform sneakers bursting off sprint starting blocks on a Gold Coast beachfront path lined with Norfolk pines, while Jason sits in a rusty old ute that coughs smoke and hasn't moved — Instant torque: already gone while the old ute is still clearing its throat.

This is general advice: compare motors on how they perform on a similar boat at the speeds you actually use, not on the headline number alone.

Why bigger isn't always better

In petrol boating, horsepower is king. In electric boating, efficiency is what counts, because the battery holds a fixed amount of energy. And speed eats that energy fast. As a rough rule, doubling a boat's speed takes about eight times the power. That's why most electric boats are designed to cruise at sensible speeds rather than blast around flat out. (Our post on how far an electric boat can go explains this in more detail.)

Choosing a motor comes down to four things:

How heavy the boat is. Heavier boats need more power.
How fast you want to cruise. A little more speed takes a lot more power.
How big the battery is. A bigger battery gives more time on the water but adds weight.
How you use the boat. Short blasts and long, gentle cruises suit different set-ups.

The general principle is to match the motor to the hull rather than overpower it. It's like choosing a hammer: a sledgehammer isn't better for hanging a picture, just heavier and harder to control.

Cartoon of Jason wobbling under a giant sledgehammer to hang a tiny beach picture on a Queenslander verandah, while DJ in a white crochet cardigan and pink flared jeans leans on a post laughing and offers him a normal hammer, as a blue-tongue lizard watches — Bigger isn't better. Match the motor to the hull, not the ego.

Two motors, two hulls

Many catamarans use twin motors, one for each hull. That has some handy benefits. Run one motor forward and the other in reverse, and the boat can turn in its own length, which makes docking and tight spots much easier. It's like two rowers in a dinghy pulling in opposite directions to spin on the spot. In general, two motors also give you a level of backup that a single motor can't.

Cartoon of Jason and DJ, in a sun hat, white crochet cardigan and pink flared jeans, paddling in opposite directions on a round orange pool ring so it spins on the spot on a mangrove-lined estuary, watched by an unimpressed pelican on a post — One forward, one reverse: spinning on the spot. The pelican has seen it all before.

What Cat Cruisers uses

Every Cat Cruiser has twin electric motors. The 650 has two 5 kW motors and the 870 has two 10 kW motors. We don't need huge power figures, because the boats are built to cruise quietly and efficiently rather than race. They draw from a 60 kWh drive battery (a kilowatt-hour is the unit on your power bill). A separate house battery looks after life on board, and 5,000 W of roof solar helps stretch a sunny day.

Want to talk motors, power and how it all fits together? Have a chat with the team at catcruisers.com.au/contact.

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