Plastic leaf rakes run up the main halyard, so
the plastic tines are above masthead are popular in a nearby harbor with a big problem like yours. They also attach some kind of lightweight longish (4-5 inches) spikes on the masthead.Also the marina company will send the boats owner a registered letter advising them they are violating a marina policy of unregistered liveaboards (the birds) and to cease & desist, at least mine probably would.