Rule 15
Acquiring Right of Way
Rule 15 - ACQUIRING RIGHT OF WAY
When a boat acquires right of way, she shall initially give the other boat room to keep clear, unless she acquires right of way because of the other boat’s actions.
Note
Remember that you are under no obligation to anticipate that a boat will acquire right-of-way over you.
In other words, you do not need to start keeping clear until the other boat actually has right-of-way.
Relevant Definitions
Keep Clear
A boat keeps clear of a right-of-way boat
(a) if the right-of-way boat can sail her course with no need to take avoiding action and,
(b) when the boats are overlapped, if the right-of-way boat can also change course in both directions without immediately making contact.
Room
The space a boat needs in the existing conditions, including space to comply with her obligations under the rules of Part 2 and rule 31, while maneuvering promptly in a seamanlike way.
Examples:
Yellow, establishing a Leeward Overlap with Blue
In Position...
Blue has right-of-way as the Clear Ahead boat, under Rule 12.
Yellow has established an overlap, and as the Leeward Boat, Yellow has acquired right-of-way under Rule 11.
However, in Position 2, Blue cannot change course without making contact with Yellow, meaning that Blue does not have the room to keep clear.
Yellow, having just acquired right-of-way, is obligated to initially give Blue room to keep clear. In this example, Yellow has not done so, and has broken Rule 15.
Yellow, tacking close to Blue
In Position...
Yellow is Clear Ahead, and is therefore the right-of-way boat under Rule 12.
Yellow has passed head-to-wind, and is now the keep-clear boat under Rule 13.
Yellow has completed their tack, is on Starboard, and is now the right-of-way boat under Rule 10.
However, in Position 3, contact is imminent, and there is nowhere for Blue to go.
Yellow, having just acquired right-of-way, is obligated to initially give Blue room to keep clear. In this example, Yellow has not done so, and has broken Rule 15.
Blue, tacking close to Yellow
In Position...
Blue is Clear Ahead, and is therefore the right-of-way boat under Rule 12.
Blue has passed head-to-wind, and is not the keep-clear boat under Rule 13.
Blue has completed their tack onto Port, and is now the keep clear boat under Rule 10.
But... in Position 3, contact is imminent and there is nowhere for Blue to go.
Yellow has just acquired right-of-way, is she obligated to initially give Blue room to keep clear?
No, because Yellow acquired right-of-way as a result of the other boat's actions.
In this case, Blue has simply broken Rule 10.