Within a single week readers sent me two questions on the same topic: How do the rules work between boats on opposite tacks coming into a leeward mark to be passed or rounded to starboard?

One reader was looking for “the rule dealing with downwind finishes,” but of course they couldn’t find it because there is no single rule that covers only those situations. Both readers commented that under the 2008 rules there was a sentence in the preamble to Part 2’s Section C stating that when the mark-rounding rule, Rule 18, applied, it took “precedence” over the port-starboard rule, Rule 10, but they couldn’t find that either. That sentence is no longer in the rulebook. There are several ways in which the current rules differ from the 2008 rules, but the “game” at leeward marks left to starboard has not changed. Here’s how the current rules apply to Peter, Paul, and Mary’s predicament shown in the first diagram.

Peter, Paul, and Mary had been on the courses shown for several lengths. Peter and Paul were overlapped on port tack as they entered the zone at the pin end of the finishing line. Mary was on starboard tack on a collision course with Paul. Mary hailed “Starboard,” and Peter hailed “Room.”

Clearly, Peter had an inside overlap on Paul. All three boats had been sailing more than 90 degrees off the wind for some time. Not so obvious is that both Peter and Paul had inside overlaps on Mary and they had those overlaps even before they reached the zone. This is implied by a new-in-2009 sentence in the definition Clear Astern and Clear Ahead; Overlap that tells you that the term overlap applies to boats on opposite tacks when “Rule 18 applies” or “both boats are sailing more than ninety degrees from the true wind.”