Along with this awesome sea lion photobomb pic, a jellywatch.org user reports over 100 sea nettles in Monterey, California on Friday, saying:
Sea nettles are back in the Monterey marina in large numbers. Usually there are all sizes from tiny to large, but this time they are mostly large
Be careful swimming folks, these guys can pack a sting. Pee also won’t likely help much, try lidocaine to neutralizing stinging cells and for pain relief.