What I forgot.

 Gave a chat at the NSSA SH Team Racing and wish I had remembered to mention that Rule 15 often comes into play on the run when the boat going left down the run or just on the left gybes onto starboard.

They gain right of way but Rule 15 requires them to initially give the other boat room to Keep Clear. The other boat generally being on port has to gybe in order to keep clear. Here comes the problem for the Umpires "Room" is " while manoeuvering promptly in a seamanlike way" 

Should conditions be light is it seamanlike to not allow the boom to swing out and hit the other boat after the gybe? If the wind is strong then the boom has to come out or a dinghy risks capsizing, a keelboat may risk a broach. But when does the wind get light enough that we expect a sailor to hold the boom?