Though considered Deadly, not all Jellyfish fall in to the category of being a Deadly creature. There are several hundred Jellyfish varieties, however, not all are poisonous or deadly. Advice would be to keep off those with longer tentacles as they would be the poisonous type and only be careful with the one's with short tentacles.
Keeping the deadly aspect aside, Jellyfish are some of the most beautiful scenery you could see underwater.
