Garmin Reactor 40 Hydraulic Autopilot

Editor’s Report

Garmin Reactor 40 Hydraulic Autopilot

Navigation Made Easy

Garmin PIC1

The Garmin Reactor 40 Hydraulic Autopilot is a compact, dependable and easy-to-install system designed to fit any recreational powerboat with hydraulic steering.

The Garmin Reactor 40 Hydraulic Autopilot can be installed on boats with inboard engines, sterndrives or outboard engines, gas or diesel. A steer-by-wire version is also available for boats with digital steering.

It’s designed to give operators the extra hand sometimes needed inshore or off, particularly when operating short-handed, making long runs in rough water or when trolling for fish.

Auto-pilot systems ease steering chores and can actually save money for boaters that make repeated long runs in areas with high current or frequently rough seas because they can help a boat track much truer than even an experienced helmsman can steer it, hour after hour.

For Operating Short-Handed

If you’re operating your boat alone, the auto-pilot function presents obvious advantages, allowing you to grab a drink or a sandwich from the cooler while the boat stays on course and underway.

Of course, there are safety considerations anytime you operate single-handed, and it’s always wise to keep the kill switch attached to your PFD as much as possible or use an electronic tethering system to assure the boat will stop should you somehow fall overboard.

For Handling Rough Seas and Strong Currents

Piloting a boat in challenging conditions and maintaining any sort of steady course can be a real challenge at times, especially over extended periods. It’s just plain exhausting to fight big seas hour after hour.

The autopilot not only takes away the physical challenge of hanging on and maintaining a steady course, but it also steers a much straighter course than even most expert skippers can manage, constantly adjusting back to the true course when knocked offline by wind and seas.

This not only assures you arrive right where you want to—maybe hitting a poorly marked inlet after a long crossing—but also can actually save time and fuel, since the auto-pilot takes the most direct route possible.

For Fishing

For anglers operating at trolling speed, the advantages are obvious, allowing rod handling and fish landing without constantly adjusting course. (Though, of course, even at trolling speed you must always keep an eye on the water ahead and be alert for approaching traffic.)

The system linked to a Garmin MFD or GPS can also follow a preset trolling pattern, along a ledge, for example, or make a figure 8 loop around bait schools without constant manual course adjustment.

You can also map out a route on Garmin MFDs and feed it into the autopilot, causing the boat to follow your pre-set course through a number of waypoints.


A quality autopilot saves fuel by steering the most direct route possible to waypoints and also reduces operator fatigue on long runs in rough water where constant course correction is required. (Regulator)

Touch the screen, push “Go To” and the autopilot takes you to that spot by the most direct route. (Of course, if there’s a shoal or a marker (or another boat) in the way, that’s a problem so it always has to be used with discretion and a sharp watch.)

Add the “Shadow Drive” option and you can alter course simply by turning the wheel to avoid obstructions or markers. After you let the wheel go, the autopilot alters course to head back to your original course.

Garmin PIC3

The Garmin Shadow Drive option added to the Reactor 40 system allows operators to take command from the autopilot by simply turning the wheel.

Reactor 40 Features:

  • With its advanced solid-state 9-axis AHRS, you can mount the Reactor 40 nearly anywhere, in any orientation.
  • The system reacts to sea conditions, so you can remain confident of your course even when the boat is pitching, yawing or rolling.
  • Commissioning and calibration are quick and easy
  • Control your autopilot from anywhere on your boat by using compatible Garmin devices, including the Reactor autopilot remote and select Quatix marine smartwatches. (Requires a compatible Garmin chartplotter or GHC 50 autopilot instrument)
  • This corepack allows for optional Shadow Drive technology to automatically disengage the autopilot when you turn the wheel
  • Combine the Reactor 40 hydraulic autopilot with the GHC 50 autopilot instrument to add a dedicated touchscreen autopilot display to your helm. Plus, GHC 50 allows you to share data and settings with Garmin MFDs and other installed Garmin devices


Autopilots are particularly useful for fishing, where the system can be set to track straight ahead at trolling speed while anglers tend rods or boat fish. (Grady-White)

The system can smoothly perform a variety of preprogrammed trolling and search procedures. Plus, with a compatible Garmin networked chartplotter and BlueChart® g2 Vision® charts (sold separately), you gain optional features such as Auto Guidance, which automatically steers GPS paths.

For just about any boater or angler who regularly makes extended runs in open water, an autopilot like the Garmin Reactor 40 Hydraulic makes life afloat easier, safer and more fun. For some operators, it may even save money in the long run.