Whether or not you plan any large passages, or do your boating locally, an autopilot enhances your time afloat.
At its simplest, an autopilot is a system that maintains a boat's heading on a chosen course, but it offers a lot more besides. Or to put it another way, it acts just like a second pair of hands while you are driving the boat. To understand the benefits, let's take a more detailed look.
What is an autopilot?
An autopilot steers the boat for you by:
- knowing which course is required via manual commands from a person who is driving the boat or automatic inputs from electronic navigation equipment
- understanding which way the boat is headed by receiving inputs from a heading sensor and drawing from other dynamic data if integrated with a full marine electronic system
- applying changes to the steering system to keep the boat on its desired course
The most basic autopilot controls have always been buttons or rotary controls to tell the system to activate, hold the current course, or steer left or right. Modern autopilots can also automatically follow charted courses if integrated with marine charting and position fixing equipment.
Early leisure autopilots used to have additional controls on the fascia to fine-tune the response of the system, such as the rudder rate (how fast the steering reacts). You may still find some of these units on boats built in the 1960s-1980s. Mastering these settings to achieve a steady course in all sea conditions was something of an essential part, albeit a very satisfying one.
Modern autopilot systems do still rely on initial calibration and set-up to work well, but they have built-in intelligence that enables them to learn how any given sea state, wind, vessel speed, loading and engine setting is affecting the boat. In any 'driving in a straight line' shoot out between a human and an autopilot in charge, the autopilot would normally win without constant pressing of buttons to adjust settings.
Speaking of buttons, in the Simrad® fully integrated world of marine electronics, you can now control your autopilot from multiple dedicated controllers, multi-function displays (MFDs) and wireless controllers.
What's in the box?
If you have a small motor launch or sloep where you steer the boat using a tiller, then Simrad® has a range of completely integrated tiller pilots where everything is packaged as one unit.
Most motorboats though use a component-based system, with many options to deal with a very wide range of boat sizes and types. Here's what a typical installation looks like:
- The autopilot computer – typically a black box that is installed out of sight. It forms the heart of the system.
- One or more standalone autopilot controllers or MFDs to control the autopilot – Simrad® also offers wireless controllers. As a minimum you should plan to be able to control the autopilot at any driving position where you operate the boat.
- An electronic heading sensor to generate direction, rate of turn and other dynamic information that assist autopilot performance. This might use solid-state electronics to read the Earth's magnetic field and boat movement, or additionally receive GPS satellite data for enhanced performance.
- A drive unit to control the boat's steering. This is typically either a hydraulic pump or steering ram with different versions available to suit outboards, sterndrives, IPS drives and rudders.
- A feedback unit to sense where the rudders or drives are pointed – this is not always required on Simrad ® autopilots.
Autopilot installation and calibration is possible by a competent boat owner. However, if in any doubt then talk to your local Simrad® dealer to ensure you get the very best out of your purchase and have a safe system that you can rely on.
What would I use an autopilot for?
- Short-handed boating
An autopilot looks after accurate course keeping, freeing up your attention to maintain a good lookout for other boats and hazards, monitor instruments and cross-reference your navigation information.
Maintaining a constant heading is of great help in assessing the risk of a collision with another vessel. If your heading remains the same and the target you are concerned about stays at a constant bearing in relation to your boat (visually or on radar), then it's time to take early action. If you drift either side of your course it's harder for you to visualise what is happening and also harder for the other boat or vessel to work out what you are doing.
In conditions of poor visibility the autopilot greatly helps avoid the disorientation you would otherwise experience when manual steering. The only other way to avoid this is to keep eyes constantly locked on the compass or rolling road display of your marine electronics. Knowing that your heading is being maintained to the desired course by the autopilot will greatly assist your own workload, providing more time to maintain a good lookout visually and on the radar.
Reaching open water and being able to set the autopilot to hold a course or follow your navigation track frees you from rigidly holding the wheel and enables you to enjoy the day more. You must, of course, keep a good watch at all times, but being able to step away from the helm is a bonus on any boat and for slower cruisers, it can make a long passage considerably easier.
Taking that a step further, you'll probably find that the convenience of steering with buttons, a rotary control or joystick is so much easier, that you spend much of your time on autopilot.
Even for faster passages, it's nice for the crew to have a toilet break and pause for drinks and snacks. Rather than stopping the boat altogether and letting it wallow in any waves, you can reduce speed to just a few knots, placing the boat on a comfortable heading in relation to the sea and pop the autopilot on to look after things. The break in the journey will be appreciated by all aboard.
It's not unusual to see someone who is hand steering wander either side of the desired course. The reasons for this include inattention, fatigue, a tendency that some people have to over-correct, or even directional instability in your boat.
This can add considerably to the distance traveled through the water. Excessive helm corrections also add drag. An autopilot that is calibrated correctly will steer an efficient course, which will save fuel.
If the boat is doing the steering, then you can also pay more attention to trim and stabilisation if fitted, to optimise those also for the perfect cruise configuration.
If you do your boating alone or have crew of limited capability, an autopilot really comes into its own. As soon as you reach a safe area of water you can leave the engines in idle ahead with the boat on autopilot to clear lines and fenders away, ensuring of course to keep a careful eye around you.
Once out at sea, the autopilot is like a second crew member, reducing your fatigue and freeing time to keep the boat safe and sound.