The bell of the lion’s mane jelly (Cyanea capillata) can grow to 6½ feet (2m) across, and the tentacles can extend outward for 30 feet (9m)! These tentacles will deliver a nasty sting to a diver and can sometimes be difficult to see in the water. 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 meat tenderizer or vinegar is a good antidote. Although as a diver it’s good to be careful around the lion’s mane jelly, it is very interesting to observe one up close. This pelagic jelly has a west coast range from northern Alaska to southern California.