[FWIW]   A jellyfish sidebar; ...been smacked at least once.

While snorkeling off a rocky Okinawa shoreline back in 85, a pal & I, his lovely bride sunning on the beach with a pitcher of Mai Tai & a good book, were exploring along the rock walls looking for cave entrances 5-10 ft. or so below the sea surface.  A fun pastime for anybody who can get out that way and give it a whirl.  Well...sure enough we found this four ft. by four ft. opening and swam in to find the kind of thing I’ve, personally, only seen in Okinawa.  A seaside cave, only accessible from under water best we could gather, about the size of a small living room w/loft.  With three levels of ledges going up the rock walls..., which, upon climbing to the top, put us at a challenging diving height over a beautiful crystal clear emerald-blue pool, ...& we could see all 15-20 feet or so to the bottom.  A beam of sunlight shining through a smallish hole in the cave roof hit the top of the pool, refracted just a bit and continued...visible all the way to the bottom rocks.  ...I’m talking a moment of perfection here...a sigh of visual flawlessness..........before the diving in and climbing back up...and diving back in...rinse...& repeat began for a couple of hours, which passed like thirty minutes outside of a good dream.  What a blast, ...could do it every day for the rest of my life and...never...tire of it.  But it began to get late...and the tide started coming in...& anybody who’s ever swum the beaches of Okinawa knows that means smacks of jellyfish of every conceivable size and shape and oddity are riding in on the tide...at most every level. 

As they began to feed in through our only way out...we both had the same realization.  ...We’ve got formation in the morning ~~ which is the kiss-of-death to miss for any reason, one sweet semi-drunk young lady on the beach is very likely now starting to freak-out...and we’re kind’a trapped here.  ...Now they’re groovy to look at from a distance but jellyfish mostly suck.  & they’re not all alarmingly hazardous...but we didn’t know enough about them to know which ones were the nastiest...and we could actually identify a few, like the dreaded “box” for instance, that we KNEW were not to be rubbed up against if a tomorrow without suffering is on the schedule.

So we did the only thing we could do.  We agreed to take a deep breath, dive down to the bottom & swim out...under them, backs or bellies on the floor...just below the lowest ranks of jellies (hundreds of those ominous little floating, ...never knowing where their going to bobber to, ...slow colorful and hypnotic little multi-tiered and ornamented bubbles with masses of stinging tentacles trailing off of them, ...all too many already inside the cave and as far as the eye could see once outside the little exit hole.)   We were wearing wetsuits ( & fins/fin socks/goggles) or I figure we’d both have been stung [by at least the common ouch-class of jellies].  Still cannot believe we held our breath that long.  I have no clue how anybody gets out of these extreme little tangles when we’re young, ...but we did; & not too bad off for the wear...accept for a hesitation about evening swims...and one pizzed-off & worried, slightly-buzzed-&-actually-quite-stunningly-elegant-in-her-fury, wife on the beach...when we got back.