Rupert Holmes takes a detailed look at the current state-of-the-art autopilot sailing systems and investigates what the future holds
A couple of decades ago I’d have recommended anyone planning an ocean crossing without a big crew to fit wind vane self-steering. Yet in the past five years I’ve sailed more than 20,000 miles, including multiple trips to the Azores and a transatlantic race, relying solely on electronic pilots whether double-handed or solo.
This change is also borne out by the few yachts taking part in the ARC that are still seen with wind vane steering systems. So what has changed in the intervening time? And what can we expect in the next few years?
Firstly, electronics have become much more reliable. We also have many more ways of generating the electricity needed to run them. Most yachts set up for sailing longer distances are therefore no longer primarily reliant on the main engine for charging batteries thanks to solar, hydrogenerators, fuel cells and so on.
Finally, compared to the total cost of preparing a yacht for long-distance sailing, fitting a second pilot that’s not reliant on the boat’s main instrument databus is not unduly expensive. If you think having such a back-up is overkill, it’s the approach most of the top short-handed offshore race boats take. And there’s no way they’d carry unwarranted extra weight.
Nevertheless, it’s important to recognise that a back-up pilot is yet another item that needs to be maintained if it is to be relied on at sea.
Today’s units will also steer a far more accurate course, even in very challenging conditions, than early models. If your pilot is close to a decade old the chances are a newer model will steer the boat more accurately. Yet very often the pilot computer of quality yachts only gets replaced when it malfunctions and I’ve seen many immaculately maintained boats from the 1980s and 1990s with their original equipment. It may have been top specification in its day, but new kit will be enormously better.
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Even so, most pilots today are not as good as an alert and skilled crewmember. In offshore racing circles there has been debate about whether pilots should be allowed for fully crewed boats, as well as for short-handed competitors. As a two-handed and solo racer myself I’ve always said “bring it on”.
Outside the realm of the top Class 40s, IMOCA 60s and Ultime trimarans, pilots today are not as fast as a human driver. The prevalence of two-handed boats with someone on the helm for the overwhelming majority of every offshore race is testament to that.
RORC’s 2020 Notice of Race recognises this and permits the use of autopilots and wind vane steering for all competitors.
Autopilot set-up and trimming
To get the best results from most pilots you have to adjust the unit’s settings to suit both your boat and prevailing conditions. Yet this is often something that’s not well understood. For example, Navico CEO (and past Volvo Ocean Race CEO and skipper) Knut Frostad told me he interviewed dozens of boat owners about their electronics during an 18-month transatlantic cruise with his family on their Outremer 5X.
One of the big surprises for him was the number of people who didn’t use pilots when shortening sail in difficult conditions, with many saying their unit wouldn’t cope. When he offered to help by looking at their settings, Frostad often found they were obviously incorrect, or were unchanged from factory default.
In the racing world I’ve seen similar, including a new boat at the end of a RORC season with top of the range B&G kit, yet only a couple of very basic settings, such as depth and compass calibration, had been changed to suit the boat.
The difference a properly set up pilot can make is huge. French solo racers talk in terms of ‘trimming the pilot’ in just the same way they talk about sail trim. When racing Figaro 2s British skipper Sam Matson, for instance, said he would often spend 20 minutes with the pilot after a course change to be sure the settings were optimally tuned so that it was steering as well as he could.
We don’t need to go to that level when cruising, but it’s still important to understand how to get the best from the system on your boat. Alternatively, a more recent category of pilots, such as Raymarine’s Evolution series (see below), employ artificial intelligence and so don’t need settings to be adjusted by the user.
Pilot computer: The core of the system that takes inputs from the various sensors, calculates changes in rudder angle required and activates the drive unit to achieve these.
Drive unit: The equipment that moves the rudder. This will vary depending on the type of boat and simply takes a 12V or 24V feed from the pilot computer.
Pilot controller: The user interface, which usually includes an LCD display and sometimes a remote control.
Sensors: These include rudder angle, wind speed and angle, plus a compass. Boat speed is also needed for true wind angle calculations. A gyro compass that senses the rate of turn, as well as the instantaneous heading, was often used but newer models have a solid-state 9-axis sensor that also measures heel, roll and pitch. These give more accurate data for radar overlays on chart plotters, including MARPA (Mini Automated Radar Plotting Aid) tracking of other vessels.
For optimal performance the quality of wind data is important. Given the sensor is at the masthead it moves around a great deal in big seas causing peaks and troughs in the readings. Traditionally this has been dealt with by damping the signal – taking an average reading over a longer time period – but that’s not a good option if you want a quick pilot response.
NKE gets around this with its High Resolution products that measure the boat’s motion, calculate the movement of the masthead and then uses this data to smooth the wind angle measurements in a process that takes only milliseconds. NKE says the extent to which this reduces rudder movement translates to a reduction in power consumption of up to 40%.
The company offers two levels of pilots. The NAC-3 Autopilot Computer is the basic model in the company’s Triton range that’s designed for boats over 33ft (10m). It takes inputs from the RF25 rudder angle sensor and Precision 9 compass. The latter is a solid-state unit with NMEA outputs for heading, rate of turn, pitch and roll. After calibration, heading accuracy is within 2°.
The pilot computer for the high-end H5000 systems has many more inputs, modes and algorithms that can vastly improve the accuracy of steering, even in the most challenging conditions.
Modes include Gust Response, Recovery and High Wind Response. The level of Gust Response is user selectable to control how aggressively the unit responds to an increase in heel. The Recovery function allows users to define how quickly the pilot responds to being knocked off course by waves or wind shifts. High Wind Response sees the boat bear away in sustained increases in wind speed – ideal when spinnaker reaching.
Unlike the Triton model, the H5000 also has Economy, Normal and Sport modes. In the former the pilot needs to sense large environmental changes before increasing the response setting, whereas at the other end, Sport mode is most sensitive to changing conditions and needs smaller environmental changes before increasing the response setting.
The H5000 pilot is a hugely powerful system, but time is needed to understand all the functions and which one is to best use in a particular circumstance. Even very experienced teams can struggle with these aspects.
NAC-3 Autopilot Computer: £1,566
RF25 rudder angle sensor: £290
Precision 9 compass: £628
H5000 CPUs: £1,550-£3,862
H5000 pilot computer: £2,183
This Lorient-based brand is not well known in the UK outside of the short-handed racing circuit, which it dominated for decades. NKE’s GyroPilot was developed in 1995 as the first ever unit to benefit from a gyro compass that can output the rate at which a yacht is turning as well as its instantaneous heading. The difference is dramatic, allowing the GyroPilot to safely steer a racing yacht downwind with the spinnaker set.
The system has been much refined over the years. The current 3D Sensor, for instance, is an inertial measurement unit that measures the boat’s movement and orientation to provide accurate heading, roll and pitch, acceleration and turn rate data.
The company’s Processor HR (High Resolution) and Pilot HR includes the motion reference unit for noise reduction of wind data mentioned earlier. It also benefits from further modes to improve performance in gusts and when surfing.
In gust mode the pilot will bear away during the gust, then luff up when the windspeed reduces, exactly as a human driver would when spinnaker-reaching in breezy weather. Surf mode deals with the boat’s acceleration on waves when sailing downwind, with the course adjusted to promote planing, again just like an experienced sailor.
NKE pilots can also be pre-programmed with base settings for use in different conditions, using a matrix that covers running, reaching and close-hauled wind angles in light, medium and heavy airs. Examples of these settings appear to be fairly widely shared, especially among the French short-handed sailing community.
Richard Palmer, who won last year’s RORC Transatlantic Race sailing his JPK 1010 Jangada double-handed with Jeremy Waitt, has used both a standard NKE GyroPilot and the latest HR systems. “The HR pilot certainly performs well sailing upwind to a wind angle, helped by the reduction in noise on the wind instruments,” he says.
“The HR pilot is also more efficient in most conditions and therefore reduces power consumption. However it did require quite a lot of time and effort to set up. It’s not a simple ‘plug & play’ and we are still learning how to adjust the various settings for different conditions.”
GyroPilot 2 Processor: €2,279
GyroPilot display (white): €1,063;
GyroPilot display (carbon): €1,828
Regatta processor: €6,424
HR masthead wind sensor: From €1,444
Rudder angle sensor: €362
The Reactor series of pilots is designed for both sailing and motor yachts. Both on the dock set up and commissioning at sea is required. After that there’s a user-adjustable gain setting and further parameters can be tweaked from the values calculated during the commissioning process to further improve performance.
Reactor 40 Corepack (including 9-axis sensor): £1,459
GRF10 Rudder Feedback sensor: £200
For many years autopilots have been able to ‘learn’ the sea state and therefore improve course keeping. Raymarine took this approach a long way further using artificial intelligence (AI) to create its Evolution range of pilot computers that don’t need human intervention to optimise settings for different conditions.
These use AI expertise that was originally developed by Raymarine’s parent company FLIR Systems for use in the aerospace field. As well as not having complex parameters that need changing for different sailing conditions, these products also don’t need calibration – even the compass is plug and play.
Nevertheless Race, Cruising and Leisure modes offer some user input in a manner that’s akin to some automatic cars that have economy, normal driving and sport modes.
When it was first launched the system was thoroughly tested by the short-handed racing community, who worked with Raymarine to iron out a small number of bugs that were apparent when a boat was pushed very hard. Subsequent users therefore have the assurance that if caught out in extreme circumstances the system has been tested to the limit. Nevertheless, as with many other systems, it can struggle when attempting to sail deep downwind under spinnaker, especially in a quartering sea.
EV-200 Sail system pack (excluding drive unit): £2,115
Leading-edge autopilot technology
La Rochelle-based Madintec is pioneering the most advanced pilot systems imaginable, including custom solutions for foiling boats from GC32 catamarans to 30m Ultime trimarans.
Ian Lipinski, winner of the Class 40 division in last year’s Transat Jacques Vabre, used a Madintec Madbrain pilot for the race. “As expected, the boat becomes magical from 25 knots of wind,” he reported after the finish. “She flies on the water and passes waves without slowing down. After we got out of the English Channel we never hand steered again and we beat the 24-hour distance record under autopilot!”
The firm’s most exciting area of focus is clearly on its three-dimensional pilots for foiling boats. This field is developing rapidly given that after this year’s Vendée Globe race IMOCA 60s will be allowed T-foils on their rudders so they can fully fly. At the same time, more Mini 650s are now flying, following the ground-breaking work done by Lorient-based SEAir.
The Madintec system controls both the rudders to keep the boat on course and the foils to maintain the correct ride height. This was the system used by François Gabart for his record-breaking 42-day solo circumnavigation on his Ultime trimaran MACIF.
The future of autopilots
Where will this technology eventually lead? While predicting the future is notoriously problematic, there are a number of clear trends that we can confidently expect to continue.
Talking to Shirley Robertson for her excellent podcast last year, Gabart said we can be certain that non-stop round the world times will continue to fall, with the Ultimes able to spend a far greater proportion of the distance up on their foils, even when sailed single-handed. Automated ride height control is also spreading to other parts of the foiling sphere and Gabart expects these systems to benefit from accelerated refinement at the Artemis sailing simulator in Slough, UK.
But what does this mean for cruising sailors? At a basic level, improved pilots with better algorithms and more data inputs will steer existing designs of cruising yacht more efficiently, even in demanding conditions, and without the complex tweaking of settings that is currently often needed. Importantly, accurate steering also increases a boat’s comfort at sea. The reduced motion is less tiring, less liable to create seasickness and should minimise accidents on board.
Looking further ahead it gets far more exciting. The work that companies such as Madintec are pioneering for three dimensional pilot systems for IMOCA 60s, Ultime trimarans and others will also open up the prospect of foiling cruising multihulls that don’t require a team of world-class sailors to handle them.
Granted, these boats would likely need to slow down to Archimedes mode in certain conditions. Sailing from Lanzarote with Giovanni Belgrano on his foiling MOD70 Maserati, it was clear the Atlantic swells on the day I was on board were too close together for the boat to perform at its best.
We still occasionally touched 38 knots of boat speed, but with Maserati repeatedly ploughing into the wave ahead, dropping off the foils in huge clouds of spray, with more than 10 knots knocked off our speed each time.
By contrast, an ultra-fast cruising yacht could take it easy on such days and still be sailing fast. With the benefit of today’s weather forecasting for the most part such a boat would have plenty of opportunity to skirt weather systems, staying largely in favourable conditions.
First published in the June 2020 edition of Yachting World.
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