Diving - Environment

Diver equipment being checked by dive tender and supervisor
All aspects of the diver's equipment are checked by tender and supervisor before each dive.
Photo: Andrew Cawthorn
Antarctic diving is conducted in an extreme environment, with particular environmental conditions such as cold water and sea ice to contend with. The protocols and methods we use are, however, similar to those used in scientific diving operations in other parts of the world.

Seawater temperatures along the coast, although extremely cold, vary little over the austral summer (between -1.5° C and -1.9° C). The dry suit and thermal insulation set-up we use for diving therefore doesn't change over the summer dive season (See Diving – Equipment).

Diving operations are rarely inhibited by tides (maximum tidal range is less than 2m) or strong currents and waves and ocean swell are practically non-existent along the Casey coast. Wind and surface temperature are, however, substantial issues for the comfort of diving personnel and the stability of sea ice.

Sea ice provides an excellent platform from which to conduct diving operations in early summer. Diving equipment can be driven right up to the dive site in over-snow vehicles such as Hagglunds, with the ice providing unlimited space in which to set up and lay out equipment.

Looking up at dive hole from below sea ice
Looking up to the dive hole from below the sea ice. While working in the -1.85o C water the divers may be warmer than their tenders above who are exposed to the chilly Antarctic winds
Hagglund parked on sea ice next to dive hole
Early in the season the sea ice is thick enough to allow vehicles to drive right up to the dive site. This greatly reduces the effort in diving operations.
Photo: Glenn Johnstone

With even a light wind, however, surface temperatures drop rapidly and dive personnel must be adequately prepared to work in temperatures of -15C or below.

Excessive wind can rapidly break up sea ice making through-ice diving extremely dangerous. Consequently, diving cannot be undertaken at Casey in winds exceeding 20 knots.

Casey is renowned for the fierce blizzard conditions that can rapidly descend on the area bringing strong winds, blowing snow and poor visibility. Blizzards may last several days and often cause the break-out of sea ice from the areas bays.

This page was last modified on 27 June 2002.