Sailing tactics you can train online: laylines, VMG and when to tack

Faster is not always better in a sailing boat. Sailing higher brings you closer to the mark on every mile but at a lower speed. Sailing lower is quicker through the water but towards the wrong place. Tactics starts with that trade-off.

VMG: the only speed that counts

VMG (velocity made good) is how fast you are really getting closer to where you want to go. Take the 30 ft cruiser of THE BALTIC LAP: in 12 knots of true wind she makes about 4.7 knots at 40° to the wind. Upwind, that gives about 3.6 knots of progress straight into the wind (4.7 × cos 40°).

The exercise is simple and very instructive:

1. Sail upwind and read VMG on the DATA BAR.
2. Bear away by 5°. The boat speed rises. What happens to VMG?
3. Come up by 10°. The boat speed drops. And VMG?

You will find the best angle for that wind, and it will change as the wind does. This is why navigators study polar diagrams, and % OF POTENTIAL on INSTR shows how much of the boat's polar you are making.

Laylines: when to stop going and turn

A layline is the line from which you can reach the mark on one tack, without another turn. The console draws LAYLINES to the next mark. Three mistakes cost places here:

• Overstanding: you sailed past the layline. Every extra mile on it is wasted because you are now sailing lower or further than needed.
• Reaching it too early: on the layline you have nowhere left to play. Any wind shift can only hurt you: a lift means you went too far, a header means you need two more tacks.
• Trusting the old wind: a layline is only true for the wind of this moment. A shift moves it, so check again before committing.

A useful rule: keep away from the laylines until you are near the mark, unless you know a shift is coming.

When to tack

Each tack costs some distance, so it needs a reason. Good reasons:

• You are headed: the wind has moved forward, and the other tack is now better (the WIND SHIFT gauge shows which).
• You have reached the layline.
• The coast or an island is coming up, and there is more room on the other side.
• A forecast shift is about to make the other side better.

"Because the other boats did it" is a poor reason, but sometimes a useful question: what do they know?

Downwind has the same problem

Dead downwind the same boat makes about 4.35 knots in 12 knots of wind, and on a beam reach about 6.2. So heading straight at a downwind mark is often not the quickest way there. You may gain by sailing an angle and gybing, with the kite if the wind allows. Read VMG and try it. And heeled too far under the kite she broaches, as the real boat would, so the fastest setting is not always the one you can hold unattended.

Holding an angle or a heading

HOLD HEADING keeps a compass course. HOLD WIND ANGLE keeps the angle to the true wind, so she follows the shifts by herself. Each has a price:

• A fixed heading can leave you with the wrong sails or sailing too high when the wind shifts.
• A fixed wind angle can quietly carry you far from your line, and perhaps towards land.

Which one to leave on overnight is a real tactical decision. HOLD WIND ANGLE is one of the race extras, which come with the Race Pass, Premium or a simulator subscription, or when a friend you invited joins.

Practise the mark rounding

Every mark is rounded on a set side, and the COURSE line and arc show the way round. Approach with a wide entry and a close exit, so that you do not lose ground on the next leg. Then check how much you lost compared with the boat ahead.

FAQ

Are the tactics the same in a real club race?

Wind tactics are the same. A real race adds close-quarters boat-on-boat tactics and the racing rules, which the races leave out because the boats pass through each other.

Do I need to know polar diagrams?

No. Start with VMG on the DATA BAR. Polars explain why the numbers change, and you can read them later.

Related reading

• Sailing strategy: wind shifts, choosing your side and when to follow the fleet
• Good decision or lucky outcome? How to learn from your own sailing results
• What does a skipper actually think about at sea? A beginner's guide
• Online sailing regatta simulator — a series of long races round real seas, now THE ROARING NORTH SEA
• Sailing simulator — sail trim, tacks, gybes, reefing and the kites in today's real wind, in the browser
• All articles · Open the simulator

Boat types are described generically; SkipperCheck is not affiliated with any boat builder or class association.