71 year old Lifeguard…interesting.
Dude looks good for 71.
Pretty scary experience, maybe to the shark, his buoy looked like a yellow seal. 
I’ve spent many hours diving and spearfishing and spotted many harmless sharks but just one biter and never had any problems.
I did have a friend who had an 8-ft hammerhead munch on some yellowtail he had on a stringer off Sunset Cliffs, San Diego, CA in the 1960s.