What is the fine-grained topic of the following text: Gavin who is profoundly deaf and had zero sailing experience prior to signing up for the Clipper Race, volunteered to swim between the two yachts and found four other crew onboard all incapacitated and unable to help their crewmate who had been tangled in halyards at the top of the mast for several hours. Only return the topic.
Gavin's heroic act in the Clipper Race despite being profoundly deaf and inexperienced in sailing.