Situation
Two boats, W and L, are sailing downwind in conditions where they would normally use spinnakers to finish as soon as possible.

Boat W has a problem with her spinnaker and boat L, sailing faster, establishes a leewardo overlap from clear astern and is subject to rule 17. Boat L decides not to use her spinnaker to gain a tactical advantage over W.

Both boats are sailing their fastest VMG course for a boat sailing downwind with a headsail but they are sailing a higher course than they would be able to sail if using their spinnakers. Boat W protests boat L alleging that, by not hoisting her spinnaker and not sailing a lower, faster course in order to finish as soon as possible, she is breaking rule 17. In the absence of boat W, L would have hoisted her spinnaker and sailed a faster and lower course to finish as soon as possible.

Question
Does boat L break rule 17 by not hoisting her spinnaker and not sailing a lower, faster course in order to finish as soon as possible?

Answer
No. The rules have no requirement as to which sails a boat must use at any time and a boat's Proper course is the course she would sail to finish as soon as possible in the conditions and with the sails she has set. Nor is there any requirement in the rules for a boat to finish as soon as possible and there could be a variety of reasons why a boat would not use a spinnaker, including tactical considerations. (See World Sailing Case ).