A good autopilot is the crew member that never gets tired, cold or bored. Choosing the right one is less about the brand on the box and more about matching the system — and especially the drive — to your boat. Here's how to get it right.
The four parts of an autopilot
Every modern autopilot is built from the same building blocks:
- Control head — the display and buttons you steer from.
- Course computer — the brain that decides how much helm to apply.
- Heading sensor — tells the brain which way the boat is actually pointing.
- Drive unit — the muscle that moves the rudder.
Get the first three wrong and you can upgrade them later. Get the drive wrong and the whole system underperforms — so that's where to focus.
Sail, power, and how your boat steers
The right drive depends on your steering system:
- Sailing yachts with a tiller or wheel and mechanical steering usually take a below-decks mechanical linear drive connected to a tiller arm on the rudder stock.
- Boats with hydraulic steering (many larger sail and power boats) take a hydraulic linear drive or a hydraulic pump.
- Smaller yachts can use a cockpit wheel or tiller pilot — simpler and cheaper, but less powerful and more exposed.
Sizing the drive to your displacement
This is the single most important decision. Drives are rated by boat displacement, and an undersized drive will be slow, noisy and short-lived. As a rough guide for Raymarine mechanical and hydraulic linear drives:
| Drive | Typical max displacement |
|---|---|
| Type 1 | up to ~11,000 kg |
| Type 2 | up to ~15,000–22,000 kg |
| Type 3 | up to ~35,000 kg |
You'll also choose 12V or 24V to match your boat, and — for mechanical drives — a short or long stroke to suit your steering geometry. If your boat sits near the top of a drive's range, size up.
Mechanical vs hydraulic
A mechanical linear drive pushes and pulls a tiller arm directly — simple, efficient and ideal for most sailing yachts with mechanical steering. A hydraulic drive suits boats that already have hydraulic steering or carry heavier loads. If you're not sure which your boat needs, that's exactly the kind of thing to ask us before you buy.
Don't forget installation and servicing
An autopilot is only as good as its installation. The drive must be mounted solidly, aligned correctly, and then the system needs proper dockside setup and a sea-trial to calibrate. The good news is that quality drives are fully serviceable — belts, clutches, motors and bearings can all be replaced rather than scrapping the unit. Our linear drive service and interactive exploded parts diagram make it easy to keep yours going for years.
Which brand?
Raymarine Evolution, Garmin and Simrad/B&G all make excellent, reliable autopilots, and we're dealers for all of them. A complete pack such as the Raymarine Evolution EV-200 with Type 1 linear drive takes the guesswork out by bundling the computer, sensor, control head and a matched drive.
The short version
Pick your drive by steering type and displacement first, choose 12V or 24V to match your boat, and buy a complete pack if you want it made simple. Tell us your boat's length, weight and steering, and we'll spec the right system for you.
Get a personalised autopilot recommendation →
Displacement figures are general guidance — always confirm the correct drive for your specific boat against the manufacturer's specifications, or ask our team.
