Shifty conditions, Two boats overlapped sailing to windward on Starboard tack about 0.25 metres apart. The leeward boat alters course sharply to windward and hits the windward boat. Should he give the windward boat time to keep clear?

The rule 16.1 is the easy part - Yes, when a ROW boat alters course, it must give 'room'.

Room is defined as room to avoid in a seaman-like manner.

Seaman-like is described in WS Case 103 as room for an experienced but not expert crew.

The WS Call Book for Radio Sailing  General Principles #1 through 4 and especially, #3 also says that while an RC boat can manouver faster, you still have to allow time for the skipper to see what is happening, and to decide that an action is to be taken, and then start to take it.

So while the rule part is easy, establishing the facts to apply the rule is harder. we are hearing only one side of the incident, and you say 'quarter of meter, and alters course sharply'.

If those facts are established by a Protest Committee, it sounds reasonable to find that sufficient room was not given.

John

Thanks for your answer. It should make for an interesting discussion on the shore.

If you are sailing 10 inches away from another boat and then turn sharply into the other and collide, then your "interesting discussion" on the shore may NOT be about the rules of sailing. Especially with the other skipper, never mind a protest committee.