From Wildlife Extra:
July 201. A rare and beautiful sea snail has been found by a Cornwall Wildlife Trust volunteer in Polzeath, North Cornwall. This is the first sighting of such an unusual creature in over 3 years, according to the Environmental Records Centre of Cornwall and the Isles of Scilly.
Violet sea snail
A violet sea snail, which gets its name from its vivid colour, is an oceanic drifter with a mucus bubble raft which supports them on the ocean surface. They travel with their prey in tropical and semi tropical ocean drifts therefore arriving in Cornish waters must be quite a shock! Once in a while they wash up in this part of the world, often with other exciting drifters such as goose barnacles and the infamous Portuguese Man-of-War jellyfish.