Case studies

Seconds before the start, two boats reach toward the committee-boat end of the line on the same tack. Green is the leeward boat; Blue is overlapped to windward, a little ahead, and runs out of room between Green and the committee boat.

The start gun fires and the race committee hails sail numbers and flies code flag X (individual recall). Maya sees she was over the line early (OCS) and turns back to restart, sailing back toward the pre-start side while the rest of the fleet beats away on starboard.

With the fleet pushing the line, the committee starts the sequence with code flag I. In the last minute before the gun, Sam is over the line early, near the middle.

After two general recalls the committee flies a black flag (or a U flag) for the next start. In the final minute Leo is just over the line, inside the triangle between the line and the first mark.

Lining up for a pin-end start, Ari is the leeward boat — right next to the pin — with boats stacked up to windward of her. To keep them off the favoured pin, she luffs up and holds them out.

After two general recalls the committee flies the Z flag for the next start. In the last minute Pip is just over the line, inside the triangle between the line and the first mark.

Holding her spot on the line with twenty seconds to go, Bea pushes her boom out to back the sail, stopping the boat and even edging it backwards to keep a gap to leeward.

Reaching in for a boat-end start, Luca misjudges the layline and his bow bumps the committee boat just before the gun.

Approaching the committee boat to start, Blue is overlapped to windward of Green and runs out of room. The boats touch, Blue can't fit, and Blue protests — “Green never gave me room at the mark!”

Both boats are beating to windward and their courses cross. Green has the wind on its starboard side; Red has it on the port side.

Red, on port, tacks onto starboard close ahead and to leeward of Green, who is on starboard. As Red passes head to wind and settles, Green has to change course to avoid her.

Two boats sail close-hauled side by side on the same tack, overlapped. Green is to leeward, Blue close alongside to windward. Green begins to luff, heading up toward the wind.

Port-tack Red is keeping clear by bearing away to pass astern of starboard-tack Green. Green starts to bear away too, closing the gap as Red ducks.

Two boats beat up a shoreline overlapped on starboard. Green is the leeward boat, close to the shore and running out of water; Blue is pinning her from windward. Green will run aground if she holds on.

Beating up the first leg, Nora is on port tack and a long line of starboard-tack Optis is crossing ahead. She thinks she can just cross the first one.

Crossing on port, Tom decides to tack onto starboard right on the lee bow of an oncoming starboard-tack boat, hoping to slow her and roll over the top. He tacks close ahead and to leeward.

On a big shift, two boats near each other both tack onto the new tack at the same moment. As they come out of their tacks close together, who had to keep clear?

A boat is creeping up to windward, trying to roll over Priya. Priya, the leeward boat, luffs gently to slow the windward boat and protect her wind.

Two boats converge on opposite tacks. The starboard-tack sailor yells 'Starboard!' loudly. The port-tack sailor says she didn't have to move because there was plenty of room.

Same tack upwind, Ada is just clear ahead of a faster boat coming up from astern. The astern boat noses right up close behind and starts to slide alongside to leeward.

Mid-fleet upwind, Theo is pinned: a boat sits right on his windward hip, so he can't tack without hitting her, and he's stuck in bad air.

In steady wind and flat water, a coach notices a sailor tacking and gybing again and again, seeming to squirt the boat forward each time with the turn.

Two boats sail close-hauled side by side, overlapped on the same tack. Green is to leeward, Blue close alongside to windward. Green luffs; Blue can't respond in time and the hulls touch. Blue protests, furious that Green turned into her.

On the beat, port-tack Red is keeping clear by bearing away to duck behind starboard-tack Green. Green bears away too, hunting down to close the gap. Red can no longer make it across and the boats touch. Green protests Red on port-starboard.

Crossing on port, Red tacks onto starboard right on the lee bow of an oncoming starboard-tack boat, Green. Green has to luff hard to miss Red's transom as Red settles. Red protests Green — “You're windward now, you have to keep clear of me!”

Beating along a shoreline, leeward Green is running out of water and hails “Room to tack!” to Blue, who is pinning her from windward. Blue says nothing and holds her lane. Green tacks to avoid going aground and the boats touch. Blue protests Green for tacking into her.

Three boats sail close-hauled overlapped: Green to leeward, White in the middle, Blue to windward. Green luffs. White, with nowhere to go, is pushed into Blue and they touch. Blue protests White — “You came up into me!”

Boats approach the windward mark (to be left to port) close-hauled. Green is overlapped inside Blue as the first of them reaches the three-length zone. Nearby, a third boat is about to tack onto the layline inside the zone.

A pack of Optis converges on the windward mark on starboard. As the leaders reach the three-length zone, Kai is overlapped on the inside of the boat next to him; behind, boats are stacked up.

Short of the layline, Ella tacks from port to starboard inside the zone, right in front of a boat that has been on starboard since before the zone and is fetching the mark.

Approaching the windward mark, Finn comes in on the port-tack layline and meets a starboard-tack boat also laying the mark. Finn calls for mark-room because he's the inside boat.

Squeezing around the windward mark in a crowd, Zoe's bow nudges the buoy as she rounds.

As the leaders reach the zone at the top mark, it's genuinely unclear whether Sofia (outside) and the boat inside her were overlapped at the moment the first of them reached the zone.

Noor reaches the zone clear ahead of the boat chasing her. The chaser dives inside at the very last second, shouting for room.

Approaching the windward mark, Finn comes in on the port-tack layline, overlapped inside a starboard-tack boat that is also laying the mark. Finn hails for mark-room as the inside boat, is refused, has to bear away, and protests for being denied his room.

Short of the layline, Ella tacks from port to starboard inside the zone, ending up overlapped inside a boat that has been on starboard fetching the mark since before the zone. Ella calls for mark-room as the inside boat; the boats nearly touch and she protests.

Inside and entitled to mark-room at the windward mark, Green is squeezed by outside boat Blue, who fails to give her enough room. Pinned, Green's hull touches the mark. Blue protests Green under rule 31 for touching the mark.

On a reach, Blue catches Green from clear astern and goes to pass to windward, establishing a windward overlap.

On a reaching leg, Blue comes up from clear astern and establishes a leeward overlap on Green, less than two hull lengths away.

Two boats reach along, overlapped on the same tack, toward an anchored boat sitting in their path. Both will pass it on the same side. Green is between the anchored boat and Blue.

Trying to drop onto a wave on a reach, a sailor throws his body forward sharply and stops suddenly to jerk the boat ahead.

Both boats run downwind on opposite gybes and their tracks converge. Green has the wind on her starboard side (boom out to port); Red has the wind on her port side.

Running downwind, Rishi heats it up and sails by the lee — the wind is now blowing over the same side as his sail. Another boat runs nearby on the other gybe.

It's breezy with rolling waves downwind. Dev pulls his sail in sharply again and again to get the boat surfing down the faces of the waves.

Becalmed near the leeward mark, an Opti sailor waggles the tiller back and forth to wiggle the boat forward toward the mark.

On the run, Mia catches the boat ahead and slides up to leeward of her, establishing an overlap from clear astern less than two boat-lengths away.

In a dying breeze a sailor rolls her Opti rhythmically from side to side, fanning the sail to keep it moving toward the mark.

Two boats run down to the leeward mark on the same tack. As the first of them reaches the three-length zone, Green is the inside overlapped boat (closer to the mark) and Blue is outside.

The leeward mark is a gate (two marks). Coming down overlapped on the inside, Owen is committed to rounding the left-hand gate mark; the outside boat is set up for the same one.

Rounding the leeward mark with mark-room, the inside boat swings wide on the exit and forces the outside boat — who had kept clear — up and out of her water.

Inside and overlapped at the leeward mark, Kira needs to gybe to head off down the next leg. She starts to swing wide to set up a smooth gybe.

At the leeward gate two boats run down on the same tack — one committed to the left gate mark, the other to the right — and their paths cross between the marks.

Running down to the leeward mark, Green is clear ahead of Blue as the first of them reaches the three-length zone. Blue then lunges for the inside at the last second.

Blue is clear astern as Green reaches the zone, then ranges up and gets an inside overlap once they're already inside the zone, and calls for room.

Blue is the outside overlapped boat as they reach the zone, so she owes Green mark-room. Then Blue drops back and the overlap breaks before they get to the mark.

Inside with mark-room at the leeward mark, Green rounds but swings wide on the exit, forcing outside boat Blue — who had been keeping clear — up and out of her water. Green, sure she had mark-room, protests Blue for not keeping clear.

Blue is the outside overlapped boat as the two reach the leeward-mark zone, so she owes Green mark-room. Coming in, Blue drops back, the overlap breaks, and Blue closes the door at the mark, sure she now owes nothing. The boats touch and Blue protests Green for forcing in.

Two boats race for the finishing line and will cross near the same point. Green is on starboard tack, Red on port.

Mateo's bow crosses the finishing line, but in the crowd he then has to manoeuvre back near a finishing mark and dips across the line again.

Squeezing across the line right beside the pin, an Opti's hull brushes the finishing mark as she crosses.

Starboard-tack Green stands on, confident in her rights. Port-tack Red misjudges the cross, the hulls touch, and there's damage.

Red tacks onto starboard a couple of boat lengths in front of Green, who is sailing on port. Red completes the tack and becomes the right-of-way boat.

Rounding the windward mark a little too tight, a boat lets her stern swing into the buoy. It's a clear touch.

Charging downwind, Ava sees a boat just ahead that has capsized, the sailor in the water beside it, right in her path.

Beating upwind, Jonah on port tack doesn't quite clear a starboard-tack boat, who has to luff sharply to avoid him. There's no contact and no damage, but Jonah knows he broke the rule.

Two Optis collide at a mark and one cracks her hull. The right-of-way boat says it wasn't her fault, so she keeps racing.

At the leeward mark a sailor cuts inside the buoy, leaving it on the wrong side, then carries on to the finish without going back.

A boat fouls Harper and doesn't take a penalty. Harper wants to protest so it gets sorted out on shore.

Struggling in fresh breeze, a sailor's coach motors alongside and shouts tactical advice — which way to go and when to tack.

Already well clear in the lead, a sailor deliberately turns back to sit on a rival from another club and slow her down out of spite — with no benefit to his own race.

Racing along in a good position, a sailor sees a competitor capsized and tangled in her rig, clearly in trouble and unable to free herself.

Near a shallow shore a sailor runs aground and is stuck fast; another boat is bearing down on her.

A sailor is fouled by a boat that doesn't take her turns, and the contact breaks her rudder fitting so she can't finish the race.

Starboard-tack Green stands on, confident in her rights, as port-tack Red misjudges the cross. Green makes no attempt to avoid Red; the hulls collide hard and a boat is holed. Green protests Red and assumes she's clean.

Port-tack Red fails to keep clear and forces starboard-tack Green to crash-tack. It's an obvious foul. Green, fuming, says nothing on the water, takes no flag, and lodges a written protest at the office an hour after coming ashore.