Safety

Man O'War
Stingrays
Sharks
Box Jellyfish
Weever
Sewage
Beach germs
Cyclones

Portuguese Man o'War

I've been stung a couple of times by Physalia (Portuguese Man o'War) in the Azores. On one occasion I was swimming round a fishing buoy where a detached tentacle was stuck, so the jellyfish itself was not to be seen. It felt like a wasp sting but had no lasting effects. A small rash appeared on my arm which lasted for a fortnight.
I was stung whilst diving off the Summer Isles (W Scotland) across the upper lip by a tentacle several feet in length belonging to
Lion's Mane Jellyfish well above me in the water, or so I thought! That too felt like a wasp sting or being thrown into a bed of nettles. Alarming at the time (40 ft deep) but no lasting effects. Bill Farnham (Univ. of Portsmouth) (September 1999)