The lion’s mane jelly tentacles can extend 30 feet (9m) into the water! These long tentacles are often difficult for a diver to see and can deliver a nasty sting. I remember a dive where someone had a tentacle drag across their exposed upper lip. After the dive his lip looked very swollen and he was driven to the hospital. If stung, apparently vinegar is a good antidote. Although as a diver it’s good to be careful around the lion’s mane jelly (Cyanea capillata), it is very interesting to observe one up close. This pelagic jelly has a west coast range from northern Alaska to southern California.