I was traversing Vineyard Sound today. After a vicious set of thunderstorms came though with a special marine alert. I decided that things looked clear enough to run against the tide in Quicks Hole down to Egartown. The wind unfortunately picked up in Vineyard Sound topping at 41 knots and big sea against the tide. We were down to 3 kts under power and no sails when the mayday came for a 42 foot Hunter off of West Chop whose rudder locked in extreme right hand arc or he thought he lost a steerage Bella Luna was its name we were right on top of him but a smallish power boat saved the day. The power boat pieced two lines together and rig rigged a tow to stabilize the sail boat until SeaTow, the CG and a Helo came all within 20 mins. You could hear panic in the voice of Bella Luna. The power boat was relaying all the positional stuff to the CG. Now here is the rant... the SeaTow gets on the VHF and says to the power boater in legalistic terms. "Are you the rescuer?" And. " be careful if you try to tow a rudderless sailboat you wil flip your boat". It was clear to me the SeaTow wanted a salvage claim not a tow fee and wanted to aim the value of the sailboat in a MAyday situation and was warning off the power boater for financial reward to SeaTow. As it was two SeaTow boats arrived and ultimately got Bella Luna under control and we passed by witnesses to the entire drama. The sailboat guy even waived at us as we slowly mothered by with awful winds howling and waves.