The water quality is not great. Sewage often overflows after heavy rain directly into the water at Portobello. So avoid swallowing it and have a shower as soon as possible afterwards. Swim shoes are recommended as there have been cases of people standing on weever fish. Also, watch out for the jellyfish in the summer.
Edinburgh Skinny Dipping Stories facebook group: https://www.facebook.com/groups/skinnyswimmers