The first question involves a common situation at the windward mark. As the first diagram illustrates below, Irene and Oscar were close-hauled on port tack approaching a windward mark that they were required to leave to port. They were overlapped, with Irene, the windward boat, required by Rule 11 to keep clear of Oscar, the leeward boat. When they reached the zone (position 1) they were overlapped with Irene inside Oscar, and Rule 18 began to apply between them (see Rule 18.1’s first sentence). Irene was entitled to mark-room under the first sentence of rule 18.2(b).

What was Irene entitled to? According to the definition of Mark-Room, Irene was entitled to room for three maneuvers—room “to sail to the mark,” “then room to sail her proper course while at the mark,” and “room to tack” because she was “overlapped to windward and on the inside” of Oscar. For each maneuver, Irene was entitled to the space she needed in the existing conditions to carry out the maneuver promptly in a seamanlike way (see the definition Room).

When Irene’s bow came abeam of the mark, she was no longer sailing “to the mark.” Her proper course was then to tack around the mark, and she promptly did so. As Irene tacked, Oscar, who wanted to tack as soon as Irene was out of his way, began his tack. At position 3, just after Irene passed head to wind and before Oscar luffed all the way up to head to wind, contact occurred between the starboard af corner of Irene’s transom and Oscar’s port side. There was neither damage nor injury. Each boat protested the other.

Here’s how I would’ve decided these protests. When the contact occurred, Irene had just passed head to wind and so Rule 18.2(b) no longer applied (see Rule 18.2(c)). As is often the case, the decision here depends on where the boats were a short time before the contact occurred. Rewind the movie a few frames and consider how the rules applied as Irene was heading directly into the wind. At that moment, she was still entitled to room to tack under Rule 18.2(b). Room to tack for Irene was room to make the approximately 90-degree turn from close-hauled on port tack to close-hauled on starboard. (Note that the verb “to tack” is no longer a defined term. Therefore, it has its everyday nautical meaning.) The contact between the boats occurred just after Rule 18.2(b) “switched off,” but the fact that there was contact demonstrated that, a second or so earlier while Rule 18.2(b) was still “on,” Oscar was not giving Irene either room to sail her proper course or room to tack. Therefore, Irene wins her protest and Oscar is disqualified for breaking Rule 18.2(b) just before Irene turned past head to wind.

During the short period between the time that Irene turned past head to wind and the time she completed her tack, Irene was required to keep clear of Oscar under Rule 13, and she failed to do so. Rule 13 is in Section A. Since Irene broke Rule 13 while “rounding the mark on her proper course,” she is exonerated under Rule 18.5(b). Oscar’s protest is dismissed.