Red shall keep
clear (rule 12
or 11) and give Blue mark-room
(rule 18.2(b,c) ). When
Blue passes head to wind however, she is no longer the right-of-way boat (see
last sentence of rule 18.2(c).
Now rule 13 applies and
Blue must keep clear until she is close-hauled. Thereafter rule
10 applies, and Blue is right-of-way boat again. Blue tacked so close to
Red, that Red probably had to change course before Blue's tack was completed,
and certainly had no reasonable chance to keep clear after the tack was done.
Therefore Blue probably broke rule
13 and definitely infringed rule
15 and will be penalized. See also Case
27.