Protest Room logoProtest Room
RulesCasesAsk AI
Auth not available
  • Rules Explorer
  • Case Book
  • AI Judge
New protest
  1. Home/
  2. Rules/
  3. Rule 17

Part 2 — When Boats Meet

Section B — General Limitations

17

On the Same Tack; Proper Course

If a boat clear astern becomes overlapped within two of her hull lengths to leeward of a boat on the same tack, she shall not sail above her proper course while they remain on the same tack and overlapped within that distance, unless in doing so she promptly sails astern of the other boat.

Definitions in Context

Boat

A sailboat and the crew on board, that are subject to the rules.

Proper Course

A course a boat would choose in order to sail the course as quickly as possible in the absence of the other boats referred to in the rule using the term. A boat has no proper course before her starting signal.

Related Cases

Case 7

When, after having been clear astern, a boat becomes overlapped to leeward within two of her hull lengths of the other boat, the windward boat must keep clear, but the leeward boat must initially give the windward boat room to keep clear and must not sail above her proper course. The proper course of the windward boat is not relevant.

Case 13

Before her starting signal, a leeward boat does not break a rule by sailing a course higher than the windward boat’s course.

Case 14

When, because of a difference of opinion about a leeward boat’s proper course, two boats on the same tack converge, the windward boat must keep clear. Two boats on the same leg sailing near one another may have different proper courses.

Case 46

A leeward boat is entitled to luff to her proper course, even when she has established a leeward overlap from clear astern and within two of her hull lengths of the windward boat.

Rule 16

When a right-of-way boat changes course, she shall give the other boat room to keep clear . In addition, on a beat to windward when a port-tack boat is keeping...

Rule 18

(a) Rule 18 applies between boats when they are required to leave a mark on the same side and at least one of them is in the zone . However, it does not apply -...

© 2026 Protest Room. Open source and available under MIT License