Moon jellyfish?

Tons of these little guys everywhere on the beach. Water was crystal clear and it was easy to spot them. Most of them hung out very close to the shore where little kids were playing (and a lot of people got stung very badly!!!) There were bigger ones a bit off shore where I went kayaking and took some pictures of them. I suspect they're moon jellyfish but I am not too sure. Also present were various comb jellies and small little red/greenish ones.