Autopilot for Inboard Engines: Drive Options

Inboard steering basics

Inboard engine boats steer through a rudder or a sterndrive, and the steering system that moves that rudder or drive decides which autopilot drive you need. The two main types are hydraulic steering and mechanical steering. Hydraulic steering uses fluid and a helm pump to move the rudder. Mechanical steering uses cables or a rod system.

The autopilot drive is the part that interfaces with your vessel's steering system to keep you on the right course, as Raymarine's drive unit page explains. So the first question is not which autopilot brand to buy, but what kind of steering your boat already has. For a full overview of autopilot types, see the best marine autopilot guide.

Hydraulic steering and pump drives

If your inboard boat has hydraulic steering, the autopilot will use a hydraulic pump drive. This pump connects to the hydraulic system and moves fluid to steer the boat. Raymarine lists hydraulic pumps in sizes like Type 0.5, Type 1, Type 2, and Type 3, each for different hydraulic steering volumes. The pump size must match your steering system's fluid volume, so you need to know that specification.

For a powerboat with hydraulic steering, Raymarine offers packs like the EV-100 Power Pilot for small powerboats, the EV-150 Power Pilot for small to medium powerboats, and the EV-200 Power Pilot for medium to large powerboats. These packs include the drive unit, so you do not have to source it separately. If you already have a drive, you might choose a core pack instead, which leaves the drive out. Compare complete packs in the best complete autopilot packs guide.

Mechanical steering and linear or rotary drives

If your inboard boat has mechanical steering, the autopilot uses a linear drive or a rotary drive. A linear drive pushes and pulls a rod connected to the steering linkage. A rotary drive turns a shaft that connects to the steering system. Raymarine lists Type 1 and Type 2 linear drives and rotary drives, with displacement limits like up to 11,000 kg for Type 1 and up to 20,000 kg for Type 2.

For sailboats with mechanical steering, Raymarine offers the EV-200 Sail Pilot for mid-sized sailboats and the EV-400 Sail Pilot for large sailboats. These packs include the drive, so you get a matched system. If you are replacing an old autopilot and want to keep the existing drive, a core pack might be the right choice. See the best sailboat autopilots guide for more.

What decides the drive you need

The drive you need depends on your steering type and your boat's size and weight. Raymarine's drive unit page says the drive unit is the part that interfaces with your steering system, and it lists displacement limits for each drive type. So you need to know your boat's displacement and the steering system type.

If you are not sure what steering system is installed, Raymarine advises consulting an authorized dealer. That is a good step before you order a drive. The dealer can help you identify the steering type and the right drive size. For more on hydraulic systems, see the best hydraulic autopilots guide.

Complete packs versus core packs

A complete autopilot pack includes the drive unit, the control head, and the sensors. A core pack includes the control head and sensors but leaves the drive out, so you can keep an existing drive. For an inboard boat, the choice depends on whether you have a drive already and whether it is in good condition.

If you are starting from scratch, a complete pack is simpler because everything is matched. If you are upgrading an old autopilot, a core pack lets you reuse the drive, which can save money. The site's guides compare complete packs and core packs on stated details, so you can see what each includes. Check the best autopilot core packs guide for options.

Other drive options for inboard boats

Some inboard boats have power-assisted steering, which uses a hydraulic or electric assist. Raymarine mentions that their Evolution autopilots accommodate hydraulic, mechanical, and power assisted stern drive systems. For boats with solenoid-controlled power steering, Raymarine offers the EV-300 Solenoid Pilot.

For boats with digital drive-by-wire steering, Raymarine has the EV-DBW Pilot and the EV-DBW Volvo Edition for Volvo Penta IPS or Aquamatic systems. These are separate categories, and the drive is not a traditional pump or linear drive. If your boat has drive-by-wire, you need a pack designed for that system. See the best steer-by-wire autopilots guide for more.

Questions to ask before you choose

Before you pick an autopilot for your inboard boat, ask these questions: What type of steering does my boat have? Is it hydraulic, mechanical, or power-assisted? What is my boat's displacement? Do I want to keep an existing drive or buy a complete pack?

The answers to these questions will point you to the right drive type and pack. If you are unsure, consult a dealer or the maker's manual. The installation itself is a job for a qualified installer, not something to guess at. For more on choosing a control head, see the best autopilot with control head guide.

What to pick for your situation

Questions

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

A hydraulic pump drive connects to a hydraulic steering system and moves fluid to steer. A linear drive pushes and pulls a rod connected to a mechanical steering linkage. The choice depends on your boat's steering type.

Can I use a core pack if I have an inboard engine?

Yes, a core pack leaves out the drive, so you can keep an existing drive if it is compatible. You need to make sure the existing drive matches your steering system and the autopilot's requirements.

Do I need a rudder reference unit for an inboard autopilot?

Many autopilots use a rudder reference to know the rudder position. Some systems, like Furuno's Fantum Feedback, do not require a physical rudder feedback unit for outboard or sterndrive installations. Check the maker's specifications for your system.

What if my inboard boat has power-assisted steering?

Power-assisted steering may use a solenoid or a hydraulic assist. Raymarine offers the EV-300 Solenoid Pilot for solenoid-controlled power steering. You need to match the autopilot to the specific steering system.