We had better luck with our last catch, a 6ft sandbar shark, a species whose long fins are considered excellent for soup.

Aquarium officials said sandbar sharks are not native to these waters but commons in the warmer southern seas near Okinawa.

Galapagos and Sandbar sharks glide within a few feet of my body, their eyes gleaming like buttons on a peacoat.

An official at local Ibaraki aquarium, Aqua World, said sandbar sharks are considered harmless but could mistake humans for food as they chase fish shoals.