I was recently helping someone with a Rule 18 question, where he was asking if being inside-overlapped at the zone mean that a boat was entitled to a seamanlike rounding, i.e., start a rounding tight then finish wide. I was surprised to learn that Rule 18 entitles an inside-overlapped boat to a tactical rounding, i.e., start wide, then finish tight.
(If this sounds like splitting hairs, it's not. Passing within inches of a mark when you exit it upwind is often the difference between holding a lane upwind -- or losing several boats due to being a few feet below the track of the boat just ahead of you, and getting their bad air.)
Here's my assessment; please let know if you agree or not.
Rule 18.2.a states that the outside boat shall give the inside boat mark-room. (Not room. Mark-room. This distinction is important.)
What's mark-room? Room to sail to the mark when her proper course is to sail close to it.
What's proper course? A course a boat would choose in order to sail the course and finish as soon as possible in the absence of the other boats referred to in the rule using the term.
As mentioned above, it's typically faster for a boat to round wide-then-tight, so that they're further upwind as they exit the mark.
Not that the racing rules still include a definition of room, which mentions "manoeuvring promptly in a seamanlike way". But room isn't used in rule 18, except for 18.2.c.2, which is when an outside boat becomes inside-overlapped once they're the zone, where it is still included for some reason. (Does anyone know why room s in 18.2.c.2?)
Please let me know your thoughts. To be clear, this does not pertain to an actual racing incident or protest. Just a hypothetical.