Starting a yacht at the right end of the line at target speed is very much a team game. On boats longer than 40ft, vital input comes from the bow person, trimmers, helmsman, tactician and navigator.

The role of the navigator has evolved in recent years to assist the tactician and helmsman by utilising navigation software to help the timed run into the start. Before the start of any competitive race fleet we now see over 90% of the fleet ‘pinging the ends’ of the line – GPS positioning helps us work out where the start line is and how far away we are at any moment.

We can now do the same with a modern sports watch with a GPS interface. However, to start a boat like a TP52, there is a little more to it than just GPS positioning then using course and speed over the ground; but even this information can be very useful – particularly with long start lines.

I’ve been using software to help start races since I first discovered Deckman in 1989. It was developed to aid America’s Cup starting, but in those days many crew were pretty sceptical about its merits.

To work out our sailing time to the start line, the software needs to know our boat’s polars (how fast we will sail compared to true wind speed and true wind angle). One factor we need to refine is that normally we are not able to sail at 100% polar speed in the run into the start line as we have other yachts in close proximity and more ‘dirty air’ to deal with.

Simplified version of the B&G data for the two minutes pre-start on Y3K, showing time, distance to the line and boat speed as a percentage of polars

The solution is to use separate start polars and here I tend to reduce the normal optimum upwind boat speed target by about 12-15%. I also reduce the downwind polar speeds as we don’t usually have a spinnaker when downwind sailing pre-start.

For working out our time to the line, we also need to know the tidal stream or current. Some software will try to factor it in for you, but with a lot of manoeuvring it can easily give erroneous readings and it can be best to dial it into the software manually just for the start. A good habit is always to check the current on the start boat and pin end as you ‘ping’ their positions.

If the calibration of our sailing instruments is awry it can generate big errors in the software predicted ‘time to the line’, which is exacerbated if you need to tack or gybe prior to your final run-in. Instruments often take up to 45 seconds to settle down after a manoeuvre.

Quicker systems with high-speed GPS all help, but most software has a ‘t’ feature that allows the navigator to ‘hold’ or freeze the wind while turning. A useful tip here can be to just call boat lengths to the line while turning.

For good reasons, we sometimes slow the yacht down, then ‘pull the trigger’ or increase speed in the approach. Few racing software packages can handle yacht acceleration, and the afterguard need to be aware of that.

Once we have pinged both ends of the start line, we can instantly see the line bias, but that is only true for that moment. My tip here is to give the ‘square line’ bearing and compare that with the mean true wind direction over the last five minutes. It is always worth double-checking the line bearing with a hand-bearing compass as you get the line transits (a shoreline object that you can line up with the pin or buoy end).

Helping to work out where the layline to each end of the line is a useful feature of starting software. With a couple of practices you can often then identify another transit to help you quickly find that layline in the heat of the battle.

Using a countdown in boat lengths to the layline helps the tactician a great deal, particularly in placing your yacht relative to another already approaching the start line. When sailing in current you preferably need to know the ‘tidally adjusted layline’ transit.

Article continues below…

How to win at double-handed racing – 5 top tips from a Fastnet champion

The popularity of double-handed sailing is on the rise. The Rolex Fastnet Race is the perfect case in point –…

Navigation briefing: How to anchor your yacht mid-race

There are two factors to consider when it comes to racing and anchors. One is whether you might find yourself…

It is usually a matter of the tactician’s preference whether to call ‘sailing time to the line’ or ‘time to burn’ and whether you are factoring in the time for a tack or gybe if required. My view is to switch to ‘time to burn’ from 2 minutes 30 seconds to go, though you need to specify ‘time to burn’ to the start line and your preferred start end.

Larger and heavier yachts really don’t want to be manoeuvring in the last 45 seconds prior to the start. So helping find the correct turn in is vital. One of the best yachts at starting I have raced on is the J Class yacht Velsheda, which weighs in at 143 tonnes.

The team never likes to have to alter course in the last minute as they start building speed. On a 140ft boat they use headsets for communication and the bowman has a key input in the last 30 seconds when it comes to calling the time to burn.

With practice, the crew can learn to have good confidence in the navigator’s calls using software, but it’s vital also to cross-check those calls with reality. This is particularly important in light and shifty conditions. Here you have to remember the software can’t see that shift that is 50m away from the boat. In light winds it is a useful to focus more on boat lengths to the start line (also when in the middle of a tack).

About the expert

Mike Broughton is a pro race navigator who has won many titles including World and European championships. He is a qualified MCA Master to captain superyachts and previously had a successful career in the Fleet Air Arm flying Sea King and Lynx helicopters.