No signs at all...only sign is the one signifying the NWZ has ended...
That guy sounds like the zillions of retired condo commando's we have her in FL. First off running on a plane in a no wake zone will only get you a ticket not arrested. Second like every one else said you are well within the law so do as you always have. It sounds like you are a responsible boater... way more so than the weekend warrior morons we see out all the time down here. Having delt with condo commando type cooks in the past I know this sort of thing can be VERY frustrating. Don't let it get under your skin man and keep on boating.
always remember that you are responsible for your wake and any damage it causes.
seems a little weird that he would single you/your boat out though.