I have added to the list of potential sources, the yard crane. It appears that when the yard removed my shrink wrap my main halyard became unattached. Later, when they attempted to launch my boat they found that the wind had blown the loose end of halyard such that it became entangled with a nearby light pole. They had to bring out the yard crane and hoist a man in a bosun chair up to the light pole to release my halyard. This would have put the crane boom over my boat. Maybe it fell off the crane. Who knows? My sailmaker suggested that I try the halyards and also look at the boom reef clutches. He mentioned that some older rigging systems had captured pins secured by covers with a screw into the mast fitting. I will check some more. I think my sailmaker has a point about the halyard top sheaves. If that pin fell out of there, the sheave would be adrift and the halyard would not work properly. Thanks again to everyone who took the time to make suggestions. Evil neighbor sounds about right, probably a power boater.