I've been on the opposite side of this as the skipper of a sailing yacht near Hamilton Island Airport, Queensland Australia (HTI / YBHM). The AIP says for this airport: "Yacht masts may infringe Rwy 14-32 apch slope clnc. " Typically during sailing races the finish line is not far from the Runway 14 approach and when aircraft are inbound, a call is made over marine radio to ask yachts to do their best to stay out of the way. Hopefully we share the airspace in a friendly way; I haven't heard of any go-arounds due to yacht masts here, though I suppose it's likely to have happened at some point in the past.