The medical examiner says Martin, a retired veterinarian, bled to death from deep lacerations in his legs.
Eight miles of coastline between Torrey Pines State Beach and Carlsbad remained closed over the weekend. But with no sign of the shark, authorities say they will reopen the beaches on Monday.
"We've been going there since I was 3-years-old. Not only all of his children here, but his grandchildren all spend a lot of time in those very waters today and it's just. It's just that part of it is just beyond comprehension," Jeff Martin said.
Martin says despite the shark attack, he went surfing on Saturday, and will take his children back out to the beach when it reopens.