Hydraulic Pump vs Linear Actuator Autopilots

What are the two drive types?

An autopilot drive is the part that moves the boat's steering. Two common types are hydraulic pumps and linear actuators. A hydraulic pump drive connects to a boat's hydraulic steering system and moves fluid to turn the rudder or outboard. A linear actuator drive uses a mechanical push-pull rod to move the steering linkage directly.

The choice between them is not about which is better overall. It is about which matches the steering system already on your boat. The maker's page for each drive states the steering type it suits. For example, Raymarine lists hydraulic pumps for boats with hydraulic steering, and linear drives for boats with mechanical steering. See the best hydraulic autopilots guide for listings that use hydraulic pumps.

Hydraulic pump drives

Hydraulic pump drives are designed for boats with hydraulic steering. They connect to the hydraulic lines and use a pump to move fluid, which turns the steering. Raymarine lists hydraulic pumps for boats with hydraulic steering, with different models for different steering capacities. Furuno offers NavPilot packs that include hydraulic pumps, such as the NavPilot 300/PG with PUMPOCT16-12.

A hydraulic pump drive is often part of a complete autopilot pack. The pack includes the pump, the control head, and the course computer. Some packs are sold as core packs without a drive, so you can keep an existing hydraulic pump. The drive type is a key filter on this site: you can compare listings by whether the drive is in the box. For a full system, see the best complete autopilot packs guide.

Linear actuator drives

Linear actuator drives use a mechanical rod to push and pull the steering linkage. They suit boats with mechanical or cable steering, and sometimes wheel steering. Raymarine lists a Type 1 Linear Drive Unit for boats up to a certain displacement, and a Cockpit Mk II Wheel Drive for wheel-steered sailboats.

Linear actuators are self-contained units. They do not need a hydraulic system. This can simplify the installation, but the drive must be mounted to the steering linkage. The maker's manual and a qualified installer decide the exact mounting. A linear actuator is often part of a complete pack, such as the EV-200 Sail Pilot for mid-sized sailboats with mechanical steering. For sailboat options, see the best sailboat autopilots guide.

Trade-offs in general terms

The main trade-off is integration versus simplicity. A hydraulic pump integrates with an existing hydraulic system, which can be a clean installation if the boat already has hydraulic steering. A linear actuator is a mechanical unit that works independently of hydraulics, which suits boats without hydraulic steering.

Another trade-off is the drive's physical size and mounting. Hydraulic pumps are often compact and can be mounted near the steering system. Linear actuators are longer and need space for the rod to travel. The maker's page and the installation manual give the details.

There is also a difference in how the drive responds. Hydraulic systems can be smooth, but the feel depends on the pump and the steering system. Linear actuators provide direct mechanical movement. Neither type is inherently more accurate; the performance depends on the whole autopilot system, including the heading sensor and the control algorithm. For more on drive types, see the autopilot drive types explained article.

How to choose for your boat

First, identify your boat's steering type. If you have hydraulic steering, a hydraulic pump drive is the natural match. If you have mechanical or cable steering, a linear actuator is the usual choice. If you are unsure, consult the boat's manual or an authorized dealer. Raymarine's drive unit page says to consult an authorized dealer if you are not sure how to determine the steering system.

Second, consider whether you want a complete pack or a core pack. A complete pack includes the drive, the control head, and the course computer. A core pack omits the drive, so you can keep an existing one. If your boat already has a hydraulic pump or a linear actuator, a core pack may save money. The guides on this site compare complete packs and core packs separately. See the best autopilot core packs guide for core pack options.

Third, think about the boat's size and steering capacity. Raymarine lists hydraulic pumps for different steering capacities, and linear drives for boats up to a certain displacement. Furuno's NavPilot 300 is designed for planing and semi-displacement outboard vessels from 24 to 50 feet. These figures come from the maker's pages and are the only numbers to rely on. For powerboat choices, see the best powerboat autopilots guide.

What the catalogue cannot say

The catalogue on this site lists stated details: the drive type, the steering type, the boat type, and whether the drive is in the box. It does not compare performance, reliability, or installation difficulty. Those depend on the specific boat and the installation.

The catalogue also cannot say which drive is quieter, more durable, or more accurate, because those are judgments based on measurements this site does not make. The site compares only the stated details from the maker's pages.

For installation, the maker's manual and a qualified installer are the authorities. This site gives no installation instructions. The drive mounting, the hydraulic connections, and the electrical wiring are all covered in the manual. For more on installation planning, see the autopilot installation planning article.

What to pick for your situation

Questions

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

A hydraulic pump connects to a boat's hydraulic steering system and moves fluid to turn the steering. A linear actuator uses a mechanical push-pull rod to move the steering linkage directly.

Which drive type is better for a sailboat?

It depends on the steering. Sailboats with mechanical steering often use linear actuators. Sailboats with hydraulic steering can use hydraulic pumps. The maker's page states the steering type each drive suits.

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

No. Hydraulic pumps are designed for hydraulic steering systems. For cable or mechanical steering, a linear actuator is the usual choice.

Do complete packs include the drive?

Some do. A complete pack includes the drive, the control head, and the course computer. A core pack omits the drive, so you can keep an existing one. Check the listing for 'drive in the box'.

What should I check before choosing a drive?

Identify your boat's steering type, the boat's size, and whether you want a complete or core pack. Consult the boat's manual or an authorized dealer if unsure.