Autopilots: Setting up your Autopilot

How your autopilot could get you back on the water and give you the edge when the racing resumes – Part 2

‘A full crew’ is becoming a difficult term to define in the high performance grand prix world. In the Ultim class, (32m racing trimarans), a full crew could be just six, while for an IMOCA60 a full compliment could be four.

Yet, despite the huge physical difference in size between these two classes, the common denominator is that their crews rely heavily on the autopilot to keep the boat under control while still maintaining a blistering pace.

Meanwhile, even though these offshore machines are a world apart from that of the everyday racer, the technology trickledown into mainstream racing has helped fuel the growth in shorthanded sailing and provided amateurs with the tools and confidence to compete at an impressively high level.

So, in this feature we ask some of those who regularly press their foot to the floor while relying on their pilots to explain how they get their systems up to speed.

"Making sure that your instruments are calibrated is the first and most essential part of setting up your autopilot. It’s pointless to go any further without doing this,” says solo and fully crewed offshore sailor Henry Bomby.

“Although we didn’t have autopilots on the Volvo 65s, the process of calibrating the instruments was clearly just as important and we would spend 1-2 months doing this This would allow us to build detailed calibration tables for our entire sail wardrobe over the entire range of wind speeds and angles. Clearly, on say a normal 40footer you wouldn’t spend this much time, but you do need to make sure it’s right and that does take time.”

“If the boat speed calibration is out then calculations like the true wind speed and direction will also be out which will start a knock on effect elsewhere.

“The speed sensor needs to be directly on the centreline too.

“Then there is the wind speed and direction, the wind vane must be centralised both physically and electronically in the set up on the instruments.”

Setting up for calibration – Henry’s Tips

  • Look for stable conditions, flat water and 10-12 knots
  • Avoid shifty offshore breeze
  • Try and stay out of any current
  • Give yourself enough space for 10 minute runs back and forth to settle things down.
  • Observing how adjustments affect the boat’s behaviour is a large part of the process.

Points to consider:

  • A square topped mainsail will produce more upwash than a conventional pin head mainsail, so your calibration charts will need to be more detailed
  • In this case, you should have a vertical wind sensor like the WS700.

 

Using in Anger

Before you even consider functions like ‘Auto Trim’ & ‘Counter Rudder’, it is important to understand the basic data that will control autopilots, ie. apparent and true wind angles to compass heading - Which do you use and when?

Most shorthanded sailors adopt the same overall approach,” says Nigel Colley of the Solo Ocean Racing Club (SORC). “Depending on the point of sail we’re on we would use the following settings.”

  • Upwind – Apparent wind angle
  • Reaching – Compass
  • Downwind – True wind angle

“These are just starting points as there are refinements in-between depending on the conditions. For example, if there are a lot of waves upwind you will want the rudder to move faster through a wide range of movements to make sure that you don’t get put about and that you keep the speed on.

“In lighter conditions and flat water, while sailing at the same apparent wind angle, you will want much smaller and more gentle movements to minimise the drag.

“In gusty conditions and flat water, when the breeze is coming off the land, you may want something in-between to get the best out of the shifts and gusts.

“Look at how you are helming before you choose a setting and turn the pilot on. You want the pilot to steer like you have been.”

For shorthanded sailing rather than solo, views vary on whether to use the auto tack/gybe functions. Some like the auto function, some are not so keen, yet all agree that this varies depending on the sails you have set and the conditions you’re sailing in, as well as the specific cockpit layout and whether controls are close to hand.

Clearly, tacking in flat water usually presents fewer problems, while a breezy gybe in big seas requires more confidence. Nigel has a particular technique for gybing A-Sails.

 Singlehanded gybing – Nigel’s Tips

  • Set autopilot to steer to true wind angle.
  • Set up the boat and pilot at 160 degrees to the true wind.
  • Plan to go through a gybe angle of 20 degrees to dead downwind, 20 degrees out the other side plus 10 to heat up a little – so 50 degrees in total.
  • Pick your moment as you would manually ie. Wait for the wave and the boat speed to coincide.
  • Press the 10 degree button five times.
  • Get on with easing and then re-trimming the kite on the new side.

Top tips

  • Speed is your friend, don’t be timid.
  • Having said that, don’t be afraid to bail out if it is early enough to do so and still recover.
  • Make sure the boat’s upright going into the gybe.

Biogs

 Henry Bomby

Henry has competed in four Solitaire du Figaro campaigns and spent over two years racing the MOD70 trimaran Phaedo 3. An Artemis Offshore Academy graduate he joined the Volvo Ocean Race in 2017-18 aboard Dee Caffari’s ‘Turn The Tide On Plastic’. He is currently working towards an Olympic campaign in the new double-handed offshore category for the Paris Games in 2024

Nigel Colley

The owner and managing director of yacht brokerage and Jeanneau UK agents Sea Ventures, Nigel is an enthusiastic shorthanded and solo sailor. He is also one of the key figures behind the Solo Offshore Racing Club (SORC) where he regularly makes it onto the podium at the club’s key racing events, including winning the 2018 SORC season overall.

He is currently campaigning a Sun Fast 3300 and a Class 40 and has a long list of successes to his name including winning the 2017 SORC Wolf Rock Race, 2nd overall in the double handed 2010 Round Britain & Ireland Race and overall winner of the 2011 North Sea 1000 Mile Race.

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