Episode 8: "WHITE ROCK, BLUE ICE" GLACIERS AND CAVES OF ALASKA: South-East Alaska Explorers Andrew and Liz Wight venture underwater and underground to reveal a side of Alaska few have seen. Braving the freezing temperatures of marble caves, dangerous submerged tunnels and water-filled caverns with huge moving glaciers, the Wights tell the story of Alaska's extraordinarily violent geological past and present.