Cerate separated from the main body and carried by the waves at almost surface depth.
DORIS link for additional info:
https://doris.ffessm.fr/Especes/Tethys-fimbria-Tethys-686
Credit to @pgirard for identifying the species!
Among debris shaken from nets & fishing gear in the harbour.
First two photos after and before some minimal cleaning with water & brush.
Photos 7,8 & 9 with smaller pink shell found nearby for comparison: Ribbed Sunset Clam Gari costulata
https://www.inaturalist.org/observations/207476020
Will make better pictures when I get a chance (end July).
Patella ulyssiponensis ?
Will make better pictures when I get a chance (end July)