CASE 33

Rule 18.2(a) Rounding and Passing Marks and Obstructions: Giving Room; Keeping Clear: Overlapped – Basic Rule
Rule 18.3 Rounding and Passing Marks and Obstructions: Tacking at a Mark
Rule 18.5 Rounding and Passing Marks and Obstructions: Passing a Continuing Obstruction
Rule 19.1 Room to Tack at an Obstruction

A boat is entitled to room to pass to leeward of an obstruction under rule 18.2(a) even though she has tacked into the inside overlapping position. A mark being passed to leeward is not being ‘fetched’.

Question
There are breakwaters projecting from the shore at fairly regular intervals with a reasonable amount and depth of water between them. To be competitive when beating over a contrary current, it is necessary to cheat the tide by tacking into and out of the water between the various breakwaters. When two overlapped boats enter the area between two breakwaters, a question arises as follows.

SL and SW, small keel boats, enter the area close-hauled on starboard tack. In the absence of SW, SL would tack at a point where, on port tack and close-hauled, she would just clear the end of the farther breakwater. Since she is not yet in danger of running aground, however, she cannot hail SW about under rule 19.1. She must wait until SW tacks and tack with her. Both complete their tacks at position 3, at which point SW, now PL, can just fetch the end of the breakwater close-hauled, but PW has overstood and will have to bear away to pass it.

When PW obtains an inside overlap at position 3, is she entitled to room from PL to bear away to clear the breakwater?

Answer
When, after position 2, SW tacks, SL is also entitled to tack. When SW turns past head to wind, the overlap between her and SL ceases to exist, because they are now on opposite tacks. A new overlap begins just before position 3 when SL passes head to wind, and at that time the boats are about to pass an obstruction on the same side. While the breakwater is a continuous structure from the shore to its outer end, it does not qualify as a continuing obstruction since the boats are concerned only with the outer end. Therefore, rule 18.5 does not apply. Rule 18.2(a) does apply, and it requires PL to give PW room to pass the obstruction. Rule 18.3 would not have applied, even if the breakwater had been a mark as well as an obstruction, since the term ‘to fetch a mark’ means to be able to pass to windward of it without tacking.

RYA 1975/8