Brent Stephenson / Columnar basalt formations at the 180 metre high Edinburgh Hill. Zodiac full of cruise ship tourists for scale. South Shetland Islands, Antarctica, December.

Flip Nicklin / Tourists in zodiacs looking at icebergs, Alaska

Troels Jacobsen/Arcticphoto / Tourist zodiacs watch Subantarctic Fur Seals (Arctocephalus tropicalis) on the shore. Quest Bay, Gough Island, South Atlantic Islands, March 2007.

Bryan and Cherry Alexander / Two zodiacs full of passengers passing a glacier in Cierva Cove, Antarctica, February 2009.

Colin Monteath / Climbers look down on kayakers and tourists in zodiacs, Enterprise Island, Gerlache Strait, Antarctic Peninsula, Antarctica

Flip de Nooyer / Tourists in zodiacs tour icebergs, South Georgia Island