Pelagia Noctiluca or Mauve stinger jellyfish in the bay at Filiatro, Ithaki. Blown into the bay from northerly winds. They carry a nasty sting so be careful, and their tentacles were very long (I saw some at least 1m long!). Beautiful translucent colours and easily swum around, with care.
Peaceful paradise at Filiatro, Ithaki.