A diver has a close encounter with an oceanic whitetip shark (Carcharhinus longimanus) at Cat Island in the Bahamas.

Close encounter with an oceanic whitetip shark, Cat Island, Bahamas.

Young adult bull southern elephant seal (Mirounga leonina) holding young pup's head underwater trying to kill it, South Georgia Island, Southern Ocean

Nurse sharks (Ginglymostoma cirratum), being fed in Hol Chan Marine Preserve, inside the Mesoamerican Barrier Reef, Belize

Nurse sharks (Ginglymostoma cirratum), being fed in shark and ray alley, Caye Caulker, Mesoamerican Barrier Reef, Belize

Green sea turtle (Chelonia mydas), with snorkeler near Caye Caulker, inside the Mesoamerican Barrier Reef, Belize

Adult humpback whale (Megaptera novaeangliae) breaching along the west side of Chatham Strait in Alaska, United States of America

A juvenile killer whale (Orcinus orca) encountered off West Craycroft Island in Blackfish Sound, British Columbia, Canada

A small pod of killer whales (Orcinus orca) encountered off West Craycroft Island in Blackfish Sound, British Columbia, Canada

Curious adult bull walrus (Odobenus rosmarus rosmarus) approach the ship at Moffen Island in the Svalbard Archipelago, Norway, Arctic, Europe

Oceanic Sun Fish (Moon Fish or Mola Mola) and snorkeler. Azores, Portugal, Atlantic.

Cuttlefish (Sepia officinalis) Two mating head to head within minutes of first encounter. Babbacombe, Torquay, South Devon, UK (RR)