Autopilot On Boats: How Effective Is It?

Autopilot systems are a combination of electric or electronic navigation tools that steer a vessel without continual hands-on involvement. They have been used on commercial, sail, and power vessels for over a century, making navigation safer and more convenient. An autopilot system consists of a navigational component that processes information from a boat's compass or GPS, and a mechanical system to move the boat's rudder or steering gear. While autopilots are advantageous for boaters in many ways, including convenience, voyage efficiency, fuel savings, and safety, there are some disadvantages to them. For instance, if autopilot components need repair, recalibration, or replacement during a voyage, getting service, especially in foreign ports, may be difficult. Additionally, heavy weather can affect how quickly an autopilot responds with helm corrections and it may strain the electrical system.

Autopilot advantages and disadvantages

Autopilot systems on boats have been used for over a century, in various forms, and are now considered almost standard equipment on larger vessels. They can be a transformative technology, offering a range of advantages to sailors and boaters.

Advantages

Autopilot systems offer convenience, voyage efficiency, fuel savings, and increased safety. They allow sailors to leave the helm to perform other tasks or take a break, without needing to continually steer the vessel. This is especially beneficial for short- or single-handed crews. Autopilots can also save fuel by reducing cruising time, especially on vessels with a GPS interface, and they do not tire as humans do.

For anglers, pre-programmed trolling patterns can increase productivity, and many autopilot models are "self-learning", remembering helm positions to hold a course and prevent over/under steering. Autopilots can also be integrated with other onboard electronics, enabling the boat to be steered directly to a waypoint or, in the case of sailboats, on a constant wind angle.

Disadvantages

One of the main disadvantages of autopilots is the potential for technical issues and the difficulty of accessing repair services during a voyage, especially in foreign ports. Heavy weather conditions can also affect the performance of autopilots, causing them to work harder to maintain headings, which can strain the electrical system.

Water intrusion and corrosion in the computer, drive motor components, and wired connections can lead to system failure or the generation of faulty data. Additionally, the electric power required to operate an autopilot during rough weather and heavy use can be high, and sudden energy spikes can cause the unit to fail.

In certain conditions, such as heavy vessel traffic, underwater hazards, or shallow water, it may be unsafe to navigate with an engaged autopilot, and constant awareness of the surroundings is critical, even when the autopilot is in use.

Autopilot safety

Autopilot systems have been used on commercial, sail, and power vessels for over a century, making navigation safer and more convenient. However, there are several safety considerations to keep in mind when using an autopilot system on a boat.

Firstly, it is important to understand the limitations of autopilot systems. While they can maintain a steady course, most standard autopilot systems do not have the capability to detect and avoid other vessels or obstacles. As such, it is crucial to always have a crew member monitoring the surroundings and ready to take over the helm if needed. Leaving a boat unattended, even for a short period, can be dangerous and put the vessel off course.

To enhance safety, some advanced autopilot systems offer features such as collision avoidance, proximity alarms, and guard zones. These systems may integrate radar, AIS (Automatic Identification System), or GPS Chartplotter technology to detect potential hazards and trigger alarms, allowing the crew to take evasive action. However, such systems may be more expensive and are typically found on larger vessels.

Another safety consideration is the potential for autopilot failure or malfunction. It is recommended to have a backup autopilot system or an alternative steering method, such as a wind vane or manual steering, in case the primary autopilot fails. Regular maintenance and testing of the autopilot system are also important to ensure reliable performance.

Additionally, heavy weather conditions can affect the performance of autopilot systems. Strong winds, currents, or waves may cause the autopilot to work harder to maintain the desired heading, which can strain the electrical system. It is important to ensure that the vessel's electrical system can handle the power demands of the autopilot, especially during rough weather.

Furthermore, water intrusion and corrosion are significant concerns for autopilot systems. Proper waterproofing, regular cleaning, and mounting below-deck units in dry, well-ventilated areas are essential to prevent failure or the generation of faulty data.

In conclusion, while autopilot systems offer numerous benefits, they must be used with careful consideration for safety. Constant crew awareness, proper maintenance, and understanding the limitations and capabilities of the specific autopilot system are crucial for a safe and enjoyable voyage.

Autopilot systems and their components

Autopilot systems are designed to assist the operator's control of a vehicle, allowing the operator to focus on broader aspects of operations. They are a combination of electric or electronic navigation tools that steer a vessel without continual hands-on involvement.

Autopilot systems on boats or vessels can be broken down into four basic components: sensing elements, computing elements, output elements, and command elements. Some advanced autopilot systems also contain a fifth element: feedback or follow-up. This refers to signals sent as corrections are being made by the output elements to advise the autopilot of the progress being made.

The sensing elements of an autopilot system include the attitude and directional gyros, the turn coordinator, and an altitude control. These units sense the movements of the aircraft and generate electric signals that are used by the autopilot to automatically take the required corrective action needed to keep the aircraft flying as intended.

The computing element of an autopilot system interprets the sensing element data, integrates commands and navigational input, and sends signals to the output elements to move the flight controls as required to control the aircraft. An amplifier is used to strengthen the signal for processing and for use by the output devices, such as servo motors.

The output elements of an autopilot system are the servos that cause the actuation of the flight control surfaces. They are independent devices for each of the control channels that integrate into the regular flight control system. Autopilot servo designs vary depending on the method of actuation of the flight controls. Cable-actuated systems typically use electric servo motors or electro-pneumatic servos, while hydraulic actuated flight control systems use electro-hydraulic autopilot servos.

The command unit, also known as a flight controller, is the human interface of the autopilot system. It allows the pilot to input commands and tell the autopilot what to do. Flight controllers vary in complexity depending on the autopilot system. By pressing the desired function buttons, the pilot sends instruction signals to the autopilot computer, enabling it to activate the proper servos to carry out the command.

The feedback or follow-up element is responsible for reducing control surface correction as the desired flight attitude is nearly attained. Without this element, the system would continuously overcorrect, leading to unstable flight. This element generates electric feedback or follow-up signals to progressively reduce the error message in the autopilot, ensuring a stable flight path.

Autopilot technology and its evolution

Autopilot systems have been used on commercial, sail, and power vessels for over a century, in various forms, making navigation safer and more convenient. Mariners have affectionately given nicknames to autopilots, such as "Iron Mike" and "Otto".

Autopilot technology has evolved to offer numerous advantages to boaters, including convenience, voyage efficiency, fuel savings, and safety. An autopilot is a combination of electric or electronic navigation tools that steer a vessel without continual hands-on involvement. This allows sailors and boaters to tend to other activities, such as trimming sails, adjusting lines, setting anchor, or taking a short nap, without having to constantly stand at the helm.

The basic components of an autopilot system include a course computer (or central processing unit) with a compass, a drive unit that moves the rudder, and a control unit. More advanced systems may include additional features such as radar, chartplotters, and remote controls.

Autopilots come in a variety of arrangements, depending on the vessel's length, displacement, and steering type. There are above-deck units, typically found on smaller vessels with tillers or steering wheels, and below-deck units, which are more powerful and suitable for larger boats. Below-deck autopilots are more complex, require precise installation, and consume more electricity, but they offer a wider range of functions and are ideal for long-distance cruising.

In recent years, autopilot technology has seen significant developments. Modern autopilots can now learn a boat's unique reactions to different sea conditions and speeds over time, providing more precise and confident course-keeping. This evolution has made autopilots almost standard equipment on larger sail and powerboats, as they can save fuel and reduce voyage time.

While autopilot technology has greatly improved, there are still some disadvantages and limitations to consider. Autopilots rely on accurate data and proper calibration, and repairs or replacements may be difficult to obtain during a voyage, especially in foreign ports. Heavy weather conditions can also affect the responsiveness of an autopilot, straining the electrical system. Additionally, it is important to always have a crew member monitoring the vessel, even when the autopilot is engaged, to ensure safe navigation and avoid potential hazards.

In conclusion, autopilot technology has evolved significantly over the years, offering boaters a valuable tool that enhances convenience, efficiency, and safety during voyages. While autopilots provide many benefits, it is crucial to recognize their limitations and ensure proper usage, maintenance, and oversight to fully leverage their advantages.

Autopilot installation and maintenance

Autopilot systems are a combination of electric or electronic navigation tools that steer a vessel without continual hands-on involvement. They are advantageous for boaters in terms of convenience, voyage efficiency, fuel savings, and safety.

Installation

Before installing an autopilot, it is important to ensure that it is a viable project for your boat. An electrical engineer or similar professional should be engaged to survey the boat and ensure that there are accessible cable runs and suitable locations to fix the hardware.

The autopilot system should be chosen with the size, type, and speed of the boat in mind. For instance, above-deck autopilots are common on smaller sailing and power vessels (generally 40 feet and under) with tillERS OR STEERING WHEELS, while below-deck autopilots are best for sail and powerboats over 40 feet.

The autopilot system will consist of a navigational component that processes information from the boat's compass or GPS, and a mechanical system to move the boat's rudder/steering gear. The autopilot will determine which way the boat should be headed and command the mechanical system to change the rudder's position accordingly.

The autopilot will have three main components: a course computer (or central processing unit) that contains a compass, a drive unit that applies force to move the rudder, and a control unit. The drive unit can be linear, rotary, or hydraulic, depending on the type of steering system in the boat.

The following steps outline the installation process for a Raymarine Evolution Autopilot:

• Mount the display screen or control head at the helm station.
• Mount the Sensor Core (the 'brains' of the system) on the forward bulkhead in the lazarette, ensuring it is away from other equipment that may interfere with the compass.
• Install the Actuator Control Unit, which interfaces with the boat's existing SeaTalk network and acts as the power supply to the drive unit.
• Connect the drive unit (in this case, the hydraulic pump) to the steering cylinder and ultimately the rudder.
• Link the new system to the boat's chartplotter via the SeaTalk network, allowing the autopilot to tap into the plotter's navigational functionality.
• Call in a hydraulic engineer to connect the new pump, measure and make up hoses and connectors off-site, and refill the system with hydraulic oil before bleeding and testing it.
• Run through the dockside set-up using the software wizard to calibrate the system, accounting for the type of drive and factoring in rudder travel limits and hard-over timing.

Maintenance

To ensure proper functioning and prolong the life of the autopilot system, regular maintenance is required. This includes:

• Cleaning the hardware after each voyage, especially for below-deck units which should be mounted in a dry, well-ventilated area as they generate considerable heat.
• Greasing the drive connection, especially for the Octopus RS drive which has two grease nipples to keep the sliding rod and pivoting mount lubricated.
• Replacing the cables periodically, as they have a limited life (Octopus quotes 200 hours for their cables).

Tips for Safe Autopilot Use

• Brief all crew members on how to engage and disengage the autopilot.
• Maintain constant awareness 360 degrees around the vessel, even with an engaged autopilot.
• If the autopilot fails or generates suspect data, immediately disengage the unit, check the magnetic compass, and adjust as needed.
• The drive unit should have a dedicated breaker connected directly to the vessel's main electric panel.
• Check autopilot heading accuracy by "swinging the compass," which involves slowly turning the boat in a circle while the computer makes corrections.
• Be mindful of conditions where navigating with an engaged autopilot can create potentially dangerous situations, such as heavy vessel traffic, underwater hazards, or shallow water. Do not engage the autopilot while docking or maneuvering in close quarters.

Frequently asked questions