Limacia clavigera (Müller, 1776)

2 June, 2002.
The Yetts out from Dunbar on the east coast.
At 7.5 metres, a 20mm long animal on the vertical rock face. 
Water temperature 10° C.
Nikonos 5 with 35 mm lens, 2:1 extension tubes and Ikelite 50 flash.

for more information about this species go to one of the links below
OPK - Opistobranquis nudibranchs of the british isles sea slug forum