Mark-room, then a wide swing
The situation
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.
Green had mark-room and was the inside right-of-way boat through the rounding — so Blue, to windward, should have kept clear, and Green's protest looks right.
The question
Green was owed mark-room — so why might Blue's defense win?
The ruling
It flips onto Green. Mark-room is only the room she needs to sail to the mark and make a seamanlike rounding — not a licence to swing wide. By taking more than that and forcing Blue out, Green — the right-of-way boat changing course — broke rule 16.1 by failing to give the keeping-clear boat room to respond, and because she had exceeded her mark-room she gets no exoneration under rule 43. A tidy “in wide, out tight” rounding would have kept her clean; the wide exit makes her the one penalized.
Mark-room is only what you need for a seamanlike rounding — swing wide and you lose your exoneration and the protest.
Opens the situation on the boat-length grid — scrub it and see exactly how the boats meet. Free, no account needed.
Rules cited
- Rule 18.2 — Giving Mark-Room
- Rule 16.1 — Changing Course
- Rule 43 — Exoneration
See the underlying rule: Rule 18 — Mark-Room.