The short version
- The rule of thumb
- Wide in, tight out. Start the turn a little away from the mark and finish it right next to it, already on the new course.
- Why
- The exit decides the next leg. A boat that leaves the mark close and at full speed is to windward of everyone who rounded wide, in clear air, with every option open.
- Prepare early
- Every job that can be done before the mark — hoisting gear ready, the spinnaker down, the board set — should be done before the mark.
- The common mistake
- Turning in too early and too tight, which forces a wide, slow exit exactly when you want to be accelerating away.
Why roundings matter
Every boat rounds every mark, and in a close fleet the boats arrive in bunches. That makes a rounding one of the few moments where you can gain or lose several places in twenty seconds without anyone sailing faster than anyone else.
A good rounding has three parts: the approach, where you set up your line and get the boat ready; the turn, which should be one smooth curve; and the exit, where you're on the new leg's course at full speed. Most bad roundings go wrong in the approach.
Wide in, tight out
Picture the mark as the inside of a curve you want to drive at speed. If you aim straight at it and only start turning when you get there, the boat skids around and slides away from the mark on the far side. If you swing a boat length or two wide first, you can carve one smooth arc that ends with the mark just beside you and the bow pointing up the new leg.
The payoff is position, not just speed. Leaving the mark close puts you to windward of every boat that rounded wide, so they're sailing in your disturbed air and you're in clean air. It also stops a boat behind you from sneaking inside on the exit. And because you finished the turn already on your close-hauled course, you don't sail a curved, slow line up the first part of the beat.
How wide is "wide" depends on the boat. A dinghy needs perhaps a boat length; a heavy keelboat, which turns slowly, needs more and needs to start turning sooner. Practice it at an empty mark until you know where your boat starts the turn.
The leeward mark
The leeward mark is the harder rounding, because you're changing from a downwind sail plan to an upwind one and the turn ends close-hauled, the most demanding point of sail.
The approach
- Decide your line two or three boat lengths out, and set it up from where you'll exit backward: where do you want to be when the turn ends?
- Take the spinnaker down early. A douse that's still going on at the mark wrecks the turn. It's far better to sail the last few lengths under main and jib than to round with a spinnaker in the water. See Spinnaker launch and douse.
- Get the boat ready to go upwind: centerboard down, upwind controls (outhaul, cunningham, vang) set or ready to pull on, jib sheet in hand.
The turn
Start the turn while you're still a little wide, and turn smoothly rather than with one hard push of the tiller — a rudder jammed over is a brake. Trim both sails in with the turn, so they're at close-hauled trim just as the bow reaches close-hauled. Crew weight moves to the new windward side to help the boat turn and to hold it flat as it powers up.
The exit
Finish the turn alongside the mark, on your close-hauled course, with the sails trimmed. Don't keep turning past it and head up too high — that's as slow as rounding wide. The rounding isn't over until you're back at full upwind speed.
The windward mark
The windward rounding is about the approach. On a course with marks to port, the approach is normally on the starboard layline, and the cheapest mistake you can make is to overstand it — sail past the layline and reach in to the mark. See Staying inside the laylines. The second cheapest is to tack in too short and have to pinch (point too close to the wind and slow down) or take two extra tacks to get round.
The turn itself is a bear-away: from close-hauled to a run or a reach. The boat wants to turn into the wind as you bear away, especially in a breeze, so the sails must come out as the bow comes down.
Without a spinnaker
- Before the mark: ease the cunningham and outhaul if you can do it safely, and have the vang ready to ease.
- Through the turn: ease the main and jib together as you bear away, and hike hard — weight out keeps the boat flat and lets it turn.
- After the turn: board up (partly, in most dinghies), weight back, and set the jib and main for the run.
With a spinnaker
- Before the mark: everything for the hoist is ready — sheets and halyard clear, pole ready to go on, the kite in its bag or chute.
- Through the turn: same as above — sails out, boat flat. On many boats you hoist after the bear-away, once the boat is level and pointed downwind, so the spinnaker fills cleanly rather than loading up on a reach.
- After the turn: hoist, trim, and only then tidy up the upwind controls.
If there's an offset mark, it gives you a short leg to do the preparation before the run begins.
Who does what
A two-person dinghy with a spinnaker, as an example. Crews divide jobs differently; the point is to agree them before the race.
| Helm | Crew | |
|---|---|---|
| Windward approach | Picks the layline, calls the traffic | Hikes, readies the hoist |
| Windward turn | Bears away, eases the main | Eases the jib, keeps weight out |
| Windward exit | Steers flat and downwind, hoists | Pole on, trims the spinnaker |
| Leeward approach | Calls the douse, sets up wide | Douses, board down, jib ready |
| Leeward turn | Turns smoothly, trims the main in | Trims the jib in, moves to windward |
Mark-room in one paragraph
Around a mark, the Racing Rules of Sailing (rule 18, Mark-Room) add something to the normal right-of-way rules. Each mark has a zone around it, three hull lengths by default. Broadly, if you're overlapped inside another boat when the first of you reaches the zone, they must give you room to sail to the mark and round it; if you're clear ahead, the boat behind must keep clear and give you room. There are exceptions — most importantly boats on opposite tacks at a windward mark — and the room you're owed is only what you need to sail your proper course round the mark, not a wide sweep at someone else's expense. Touching a mark breaks rule 31; you can put it right by taking a One-Turn Penalty (rule 44). The details are in Mark-room.
Not the rulebook. This is a summary in our own words. The sailing instructions can change the size of the zone and other details, and the Racing Rules of Sailing are the authority.
Doing it with Sail Tactician
Questions
What does "wide in, tight out" mean?
Approach the mark a little away from it, then turn smoothly so you finish the turn right next to the mark, already on the new course. You leave to windward of boats that rounded the other way.
When should I take the spinnaker down before a leeward mark?
Early enough that it's down and stowed before you start the turn. How many boat lengths that is depends on the boat, the crew and the wind, so practice it and err on the early side.
What happens if I touch a mark?
You've broken rule 31 of the Racing Rules of Sailing. Get clear of other boats and take a One-Turn Penalty promptly, unless the sailing instructions say otherwise.
Sources
Mark-room, touching a mark and penalties from the Racing Rules of Sailing 2025–2028, rules 18, 31 and 44 and the definition Zone, described in our own words. Rounding technique adapted from Sail Tactician's in-app training guide (Mark Roundings) and standard club-racing practice. Sail Tactician behaviour from the in-app User Guide, version 3.2.
What changed
- First published.
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