Choosing · 8 minute read
How to choose a marine autopilot
Choose a marine autopilot by steering type, loaded displacement, intended use and existing electronics. Compare complete installation budgets in Australia.
Most autopilot mistakes are made in the first five minutes: a wheel pilot bought for a boat that goes offshore, a pump undersized for the cylinder, a B&G bought for a fishing boat, a Garmin bought for a race boat. The fix is to answer five questions in order, before you look at a single price.
What steering does the boat have? How heavy is it, loaded? Where and how do you use it? What electronics are already aboard? What can you spend, including installation and a handover session? Work through those and the shortlist usually writes itself. The autopilot finder on this site asks the same questions.
Key facts
- Step one
- Identify the steering: tiller, mechanical wheel, hydraulic, outboard, steer-by-wire
- Step two
- Size by loaded displacement (yachts) or cylinder volume (hydraulic)
- Step three
- Above deck for coastal, below deck for offshore
- Step four
- Match the plotter brand where you can
- Step five
- Budget for installation and instruction, not just the box
Step one: the steering decides the drive
A tiller takes a tiller pilot, a Pelagic, or a on a below deck. A mechanical wheel takes an above-deck wheel drive or a below-deck linear or . Hydraulic steering, which means nearly every power boat and many larger yachts and catamarans, takes a reversible pump. Outboards with hydraulic steering take the outboard-specific packs from Garmin, Furuno and Simrad. Steer-by-wire joystick systems take a dedicated interface pack.
If you do not know what steering you have, look under the cockpit. A quadrant with cables or a rod is mechanical. Hoses to a cylinder on the rudder stock or outboard is hydraulic.
Step two: size for the loaded boat
Yachts are sized by displacement. Use the loaded figure: light displacement plus tanks, gear, crew and a season's stores, which on a 40-footer adds a tonne or two. Compare that against the drive's rating and leave margin for a following sea. Power boats with hydraulic steering are sized by the volume of the steering cylinder, which the installer measures, and by the you want.
- Raymarine ST2000+: tiller yachts to 4.5 t
- Raymarine EV-100: tiller to 6 t, wheel to 7.5 t
- Raymarine Type 1 drives (EV-200): to 11 t
- Raymarine Type 2 and 3 (EV-400): 15–35 t
- B&G NAC-2: low-current drives, roughly 8–12 m yachts
- B&G NAC-3: high-current drives, 10 m to 18 m and beyond
- Hydraulic pumps: 80–230 cc cylinders for small pumps, larger for 1.2–2.0 L pumps
Step three: how you use the boat
Coastal day sailing and motoring tolerate a tiller pilot or wheel pilot. Overnight coastal passages, Bass Strait, the Coral Sea and anything shorthanded need a below-deck system with the drive out of the weather and the thrust to hold a course downwind. Fishing boats want pattern steering and a take-the-wheel override. Racers want true-wind steering and . Long-range motor cruisers want 24 V and a stable heading source.
Be honest about the passages you will actually make. A wheel pilot bought for coastal sailing and then taken across Bass Strait is the most common regret in this market.
Step four: the electronics already aboard
Autopilots integrate best with their own brand's plotter and instruments. A Raymarine Axiom boat should look at Evolution first; a Garmin GPSMAP boat at Reactor 40; a Simrad or B&G boat at the NAC family; a Furuno boat at NavPilot. Mixed systems work over for data, but engaging and steering from the plotter screen usually needs a brand match.
Old SeaTalk, NMEA 0183 or SimNet installations can be bridged with converters, but factor the cost and the loss of features into the decision. Sometimes the right answer is to replace the plotter at the same time.
Step five: the real budget
The box is half the cost. A below-deck installation on a yacht without a can add $2,000–4,000 of yard time. A hydraulic pack needs tee fittings, bleeding and often a rudder reference. Every system needs a fused supply, a network backbone and a handover. Add a half-day of instruction on the water, indicatively $300–600, and the total is what the autopilot actually costs.
Rule of thumb
Common mismatches to avoid
A wheel pilot on a boat over 7.5 tonnes. A tiller pilot on a boat with weather helm. A NAC-2 on a 40-footer. A racing pilot on a motor cruiser. A 12 V pilot on a 24 V boat through a converter. An outboard pilot on cable steering. Any pilot without a proper supply cable. Any pilot without someone showing you how to use it.
Questions
Frequently asked
Is a more expensive autopilot always better?
No. The best autopilot is the one matched to the steering, the displacement and the use. A $12,000 racing pilot on a motor cruiser is a poor buy; a $3,500 EV-100 Wheel on a 6-tonne coastal cruiser is an excellent one.
Should I wait for a boat show?
Boat show pricing on autopilot packs is often the best of the year, and dealers bundle installation. If your timing allows, yes.
Can one autopilot brand run everything on the boat?
Data flows between brands over NMEA 2000. Control from the plotter screen, route hand-off and alarm integration are best within one brand. Aim for a matched pilot and plotter; instruments can be mixed.
How long does an autopilot last?
Course computers and heads last ten to fifteen years. Drives, belts, pumps and clutches are wear items and need service. A well-installed system on a cruising yacht is a fifteen-year investment.
Practise autopilot operation with an instructor
Habits are learned at the helm with someone watching. The training section explains what a good instructor covers and where to find one in your state.