Electric vs Hydraulic Autopilots for Powerboats

The drive is the part that moves the steering

Every autopilot system has a control head, a heading sensor, a course computer, and a drive unit. The drive unit is the physical component that connects to your boat's steering and moves the rudder or outboard when the autopilot sends a command. For powerboats, the drive unit must be compatible with the steering system you already have.

There are two main drive types you will see in powerboat autopilot listings: hydraulic pumps and electric linear drives. Each is built for a specific style of steering, so the first question before buying an autopilot is what kind of steering your boat uses. The drive is often the most expensive part of a pack, and the one that determines whether the autopilot can physically steer your boat.

If you are new to autopilots, reviewing how the parts work together helps you read listings more clearly. The autopilot drive types explainer describes the different drives in general terms, and the marine autopilot buying guide compares packs on stated details.

Hydraulic pumps match boats with hydraulic steering

Hydraulic steering systems use hydraulic fluid to transmit helm movement to the outboard or sterndrive. A hydraulic pump autopilot connects into this system and uses a pump to generate the fluid pressure that turns the steering. These pumps are common on many powerboats, especially mid-size and larger outboard and inboard models.

Raymarine markets several power pilot autopilot packs specifically for boats with hydraulic steering, including the EV-100 Power Pilot, EV-150 Power Pilot, and EV-200 Power Pilot. Furuno's NavPilot line also offers autopilot packs that include hydraulic pumps for outboard and sterndrive installations. When a listing says 'for hydraulic steering' or names a hydraulic pump, the drive is designed for that steering type.

The hydraulic pump in a pack is sized to match the steering system's displacement, but you do not need to calculate that yourself. The listing and the maker's guide will state which displacement ranges the pump fits, as Raymarine does for its Type 0.5, Type 1, Type 2 and Type 3 hydraulic pumps. If you are unsure whether a pump matches your boat, ask an authorized dealer. The learn article on hydraulic pump flow explains what that specification means in general terms.

Electric linear drives suit cable and push-pull steering

Many smaller powerboats use mechanical cable steering or a push-pull cable system. An electric linear drive uses a motor to extend or retract a rod, which is linked to the steering mechanism. This type of drive is a common choice for boats with mechanical steering.

Raymarine describes its Type 1 Linear Drive Unit as a mechanical linear autopilot drive for boats up to 11,000 kg (24,000 lbs) displacement. That description tells you the drive is meant to work with mechanical steering, not hydraulic. The stated description on a listing is your best guide to whether a linear drive matches your boat.

Electric linear drives are distinct from rotary drives, which also serve mechanical steering but turn a wheel or spoke rather than push a rod. The rotary vs linear drive article explains the difference. If your boat has cable steering, a listing that names a linear drive is likely the right direction, but always confirm the steering type in the listing or with your dealer.

How to find out what steering your boat has

The simplest way to know your steering type is to check your boat's owner manual or ask the boat builder. If you are unsure, a marine electronics dealer can help you identify it. Raymarine's drive unit selection guide says to consult an authorized dealer if you are not sure how to determine the steering system installed on your vessel.

You can also look at the helm. Hydraulic steering has a hydraulic fluid reservoir and hoses connected to the helm pump. Mechanical steering uses a braided cable in a tube. Some boats have power-assisted steering or steer-by-wire, which are separate categories and require special autopilots. For those, you would look for a steer-by-wire pack rather than a hydraulic pump or linear drive.

Spend time on this step because the drive type is the single most important factor in choosing a pack. A wrong drive will not fit your steering system without major modification. If you are replacing an old autopilot, note whether the existing drive is still in good condition; you may be able to keep it with a core pack. The core pack without drive article discusses that option.

Comparing autopilot packs by drive type

Autopilot packs are typically marketed by the drive unit they include. A pack titled 'Power Pilot' or 'Hydraulic' will come with a hydraulic pump. A pack labeled 'Sail' or 'Mechanical' may come with a linear drive or other mechanical drive. The product title and bullet list on a listing usually state the steering type it is designed for.

When comparing listings, look for the steering type in the stated details. If the listing does not say whether the drive is hydraulic or mechanical, that missing detail is a reason to ask the seller before buying. Compare the specification across two or three packs, focusing on the drive type, the control head in the box, and the sensor included. The complete pack vs custom article explains the difference between a full system and a core pack.

A core pack omits the drive, which is for owners who already have a compatible drive and want to keep it. That option is useful if your existing drive matches your steering and you only need a new control head and sensor. For a list of core pack guides, see the best autopilot core packs page.

• Check the drive type: hydraulic pump or linear drive.
• Note whether the pack includes a control head and sensor.
• If the drive is not listed, ask the seller for the model name.
• If you plan to reuse an existing drive, verify that it matches your steering.

Questions to ask before buying

Before you settle on an electric or hydraulic autopilot, gather a few facts. The answers to these questions will point you to the right drive type and the right pack.

Start with the steering: is it hydraulic, mechanical cable, or something else? Then ask what the existing drive is, if there is one. If your boat has an electronic helm like a Volvo Penta IPS or a Yamaha Helm Master, you need a steer-by-wire specific pack, not a hydraulic pump or linear drive. The Furuno NavPilot 300-HM and NavPilot 300-IPS are examples of such packs, as listed on Furuno's autopilot page.

Also consider the installation process. An autopilot drive must be correctly connected to the steering, which is a job for a qualified marine installer. The maker's manual will provide the specific steps, but the site gives no installation instructions. Instead, prepare for a dealer quote by having your boat model, steering type, and any existing autopilot model. The installation planning article offers more context.

What to pick for your situation

Questions

Can I use a hydraulic pump autopilot on a boat with cable steering?

No, it is designed for hydraulic steering. Using it with cable steering would require converting the steering system, which is a major project and not a direct swap.

Can I use an electric linear drive with hydraulic steering?

Not directly. Linear drives are built for mechanical cable or push-pull steering. For hydraulic steering, you need a hydraulic pump drive.

What is the difference between a hydraulic pump and a linear drive?

A hydraulic pump generates fluid pressure to move the steering for hydraulic systems. A linear drive uses a motor and rod to move mechanical steering cables or linkage. Each is matched to a specific steering type.

How do I know which drive type my boat needs?

Check your steering system. Look for hydraulic fluid reservoir and hoses for hydraulic steering, or a braided cable for mechanical steering. Consult your boat manual or ask a marine electronics dealer if you are unsure.

Are there other drive types besides hydraulic and linear?

Yes, some powerboats use rotary drives for mechanical steering, and some use solenoid or steer-by-wire systems for electronically controlled helm. The autopilot listing will name the drive type it includes.

What is a core pack and why would I buy one?

A core pack omits the drive unit. You would buy it if you already have a compatible drive and want to keep it, or if you are building a custom installation. It includes the control head, sensor, and course computer.