Marine Autopilot Systems - Everything You Need to Know!

The marine world has transformed from unsafe and unplanned to advanced and controlled. Thanks to the Autopilot technology, now boaters can use it in many ways, including convenience, efficiency, less fuel consumption, and of course safety. But do you know what autopilots are in reality? Do you know how do big and small boat autopilot systems work?

Don’t worry, this post is dedicated to all the mariners who are looking for some useful info regarding marine autopilot systems.

If you are planning to buy a boat autopilot no matter for small boat or for a big vessel - the info will come handy. Here you go:

What Is a Boat Autopilot System?

An autopilot is a combination of electric or electronic navigation equipment which steers a vessel without needing continuous manual input. Autopilot for boats with mechanical steering is perfect for the single-handed and short captains apart from boaters as they can do multiple tasks with ease. One can leave the helm to trim or rig sails, set anchor, adjust lines, have food without hindrance, take a nap, or do other activities while not struggling with the helm.

Boat autopilots are widely used on powerboats, commercial, and sail vessels for more than a century. They are available in different forms and models, helping make navigation safer and hassle-free for mariners. These systems are known by many nicknames, including “Otto,” “Iron Mike,” or even “the silent crew.” Autopilots for small boats are normally available within an affordable range (below $1,000); however, with fewer features & limited capabilities. That’s the starting range, you can go for some high-end units like Garmin Autopilot GHP 20,  FURUNO Autopilot 300, Garmin Autopilot Reactor 40, and many more depending on your budget and needs.

How Does a Boat Autopilot Work?

Autopilots function pretty same like the cruise settings on a regular vehicle, with the exception that the manual control settings in a tiller/steering wheel are not required. Once your vessel is balanced on the required heading for some seconds, you just need to push the ‘Auto’ button and the autopilot will take the control. The computer has a record of the heading and modifies rudder location to make sure the vessel stays on the set course. It works efficiently in high winds & strong currents, and even in over/under steering situations.

Autopilots usually come with 3 main elements, i.e. a course computer (CPU) containing a compass, a drive unit for applying force to move the rudder, and lastly, a control unit to handle the vessel.

Different Types of Boat Autopilot Systems

Today, autopilots can be found in different arrangements, differentiated by length of the vessel, displacement as well as the steering type. They include both above-deck & below-deck autopilot systems, which we will discuss below in brief. One of the old models, wind vane, is an autopilot system that is used for transferring wind energy from a vertical air paddle on to a trim tab/water paddle attached to the rudder. These old systems vanes have been replaced by the advanced autopilot systems for boats.

Above-Deck Tiller & Wheel Autopilots

These autopilots can be easily found on small sailing and powerboats that are normally less than 40 feet with tillers/steering wheels. The above-deck tiller and autopilot systems are quite simple to use, affordable, and they use simple electric connections. Also, they are energy efficient. Given there is a wide variety of small boat autopilot systems available, they have become all the more cost-effective, even for the hobbyist boaters.

The majority of tiller autopilot systems make use of electric rams that are mounted between the tiller and a gunwale fitting to control the rudder. The computer transmits a signal to the ram for moving the tiller, which helps keep the rudder on course. Contingent upon configuration, a few units can conenct directly with the top of rudder.

Another type of above-deck autopilot system is used on boats that have steering wheels. It connects directly to the wheel drive of the vessel via a belt/toothed gears for moving the wheel and is powered by a small motor.

Below-Deck Autopilots

Below-deck autopilot systems work ideal for sail as well as powerboats that are 40 feet or more. Being larger and more powerful, these autopilots can do many more functions in comparison to above-deck units. These offer smoother and improved steering for cruising long distance. Other than that, below-deck autopilots make use of more electricity and need proper installation.

Advantages of Autopilots

Now that you know so much about autopilot systems, let’s take a look at the main advantages you get from them. No matter high-end or small boat autopilot systems, they offer multiple advantages to sailors and boaters:

• Spare fuel consumption by decreasing the cruising time, especially on boats that have a GPS interface.
• Autopilots do not tire and they have unlimited attention span. They come handy while sailing or powerboating along with a single-handed or short crew.
• Anglers can user the pre-programmed trolling patterns, making the fishing experience more productive.
• A number of autopilots are “self learning,” which implies they can memorize helm locations that are required to hold a course and avoid over- or understeering.
• It can hold a steady course without needing a helmsman. has made them pretty much the fundamental marine equipment on bigger sail and powerboats.

When Not to Use an Autopilot?

In some cases, navigating a boat using an active autopilot can lead to potentially fatal situations. For instance, when underway on waterways with heavy vessel traffic, familiar underwater risks or shallow water or regions with deployed crab pots - are two main cases where the helm must be manned. An autopilot system need not be activated when docking or steering in close-quarters.

Quick Tips for Safe Autopilot Use

• Guide all your crewmembers regarding how to engage/disengage an autopilot system, especially the one you have installed on your vessel.
• Persistent awareness 360 degrees about a vessel is critical, even if it has an engaged autopilot onboard.
• In case an autopilot fails or generates suspicious data, instantly disengage the system, check the magnetic compass and do the needful to adjust the settings.
• The majority of autopilots hardware are water-resistant, yet they should be regularly cleaned after every trip. Make sure to mount the below-deck units on a dry, well-ventilated area, given they release enough heat when in use.
• At times, the speed at which an autopilot systems sails on the course corrections might become a safety concern. Speed is measured in terms of heading change (in form of degrees) per second as the helm moves.  
• There should be a dedicated breeaker in the drive unit that needs to be attached directly to the main electric panel of the vessel.
• For checking the accuracy level of an autopilot heading, you can “swing the compass,” that slowly turns the vessel in a circle while the computer does the correction.

Keep this useful info in mind to make yourself familiar with the concept of autpilots. At present, you can choose from the popular options like Garmin autopilots, FURUNO autopilots, B&G autopilot, Simrad autopilots, and more that are known for their performance, efficiency, and reasonable prices.