ABSTRACTS BY RULE NUMBER 15 - 17  

Rule 15, Acquiring Right of Way

CASE 2
If the first of two boats to reach the zone is clear astern when she reaches it and if later the boats are overlapped when the other boat reaches the zone, rule 18.2(a), and not rule 18.2(b), applies. Rule 18.2(a) applies only while boats are overlapped and at least one of them is in the zone.
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.
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 24
When a boat becomes overlapped to leeward from clear astern, the other boat must act promptly to keep clear. When she cannot do so in a seamanlike way, she has not been given sufficient room. If she takes unnecessary action that causes contact, she fails to keep clear as required.
CASE 27
A boat is not required to anticipate that another boat will break a rule. When a boat acquires right of way as a result of her own actions, the other boat is entitled to room to keep clear.
CASE 53
A boat clear ahead need not take any action to keep clear before being overlapped to leeward from clear astern.
CASE 81
When a boat entitled to mark-room under rule 18.2(b) passes head to wind, rule 18.2(b) ceases to apply and she must comply with the applicable rule of Section A.
CASE 93
If a boat luffs immediately after she becomes overlapped to leeward of another boat and there is no seamanlike action that would enable the other boat to keep clear, the boat that luffed breaks rules 15 and 16.1. The other boat breaks rule 11, but is exonerated under rule 64.1(c).
CASE 105
When two boats are running on opposite tacks, the starboard-tack boat may change course provided she gives the port-tack boat room to keep clear.

Rule 16.1, Changing Course

CASE 6
A starboard-tack boat that tacks after a port-tack boat has borne away to go astern of her does not necessarily break a rule.
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.
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, owing to 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 25
When an inside overlapped windward boat that is entitled to mark-room sails below her proper course while at the mark, she must keep clear of the outside leeward boat, and the outside boat may luff provided that she gives the inside boat room to keep clear.
CASE 26
A right-of-way boat need not act to avoid a collision until it is clear that the other boat is not keeping clear. However, if the right-of-way boat could then have avoided the collision and the collision resulted in damage, she must be penalized under rule 14.
CASE 46
A leeward boat is entitled to sail up 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.
CASE 52
Rule 16.1 does not restrict the course of a keep-clear boat. Manoeuvring to drive another boat away from the starting line does not necessarily break this rule.
CASE 60
When a right-of-way boat changes course in such a way that a keep-clear boat, despite having taken avoiding action promptly, cannot keep clear in a seamanlike way, the right-of-way boat breaks rule 16.1.
CASE 75
When rule 18 applies, the rules of Sections A and B apply as well. When an inside overlapped right-of-way boat must gybe at a mark, she is entitled to sail her proper course until she gybes. A starboard-tack boat that changes course does not break rule 16.1 if she gives a port-tack boat adequate space to keep clear and the port-tack boat fails to take advantage of it promptly.
CASE 76
When a boat changes course she may break rule 16, even if she is sailing her
CASE 92
When a right-of-way boat changes course, the keep-clear boat is required to act only in response to what the right-of-way boat is doing at the time, not what the right-of-way boat might do subsequently.
CASE 93
If a boat luffs immediately after she becomes overlapped to leeward of another boat and there is no seamanlike action that would enable the other boat to keep clear, the boat that luffed breaks rules 15 and 16.1. The other boat breaks rule 11, but is exonerated under rule 64.1(c).
CASE 105
When two boats are running on opposite tacks, the starboard-tack boat may change course provided she gives the port-tack boat room to keep clear.
CASE 114
When a boat is entitled to room, the space she is entitled to includes space for her to keep clear of or give room to other boats when required to do so by the rules.

Rule 16.2, Changing Course

CASE 6
A starboard-tack boat that tacks after a port-tack boat has borne away to go astern of her does not necessarily break a rule.
CASE 92
When a right-of-way boat changes course, the keep-clear boat is required to act only in response to what the right-of-way boat is doing at the time, not what the right-of-way boat might do subsequently.

Rule 17, On the Same Tack; Proper Course

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.
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, owing to 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 sail up 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.