We had a good snorkel session at Nansidwell Beach with an enormous amount of two-spotted gobies about. We found some less lively fish as well on the beach: a bunch of juvenile Mackerel Scomber scombrus (already in a bit of a bad state) and also a juvenile Horse mackerel Trachurus trachurus (see here for a live one): 
They where probably too eager when chasing food up against the shore that they where washed up/standed? I would kill for a live tiny little juvenile mackerel like that to keep it in the tank for a while 😉