Pirates? We know that smugglers anchored here in the 1800s. Knights landing here? Well, not as such, but I seem to recollect a prior cache at this location which had something to do with the Cave of Caerbannog and Arthur's knights ... so that counts. And rumor has it nowadays: there is a special kind of love Letter in the Fern Grotto. 
Come prepared with a flashlight for an easy little adventure in the dark -- although it's not required to participate in the "scary" part to attend the event.
No, of course ya don't have to wade, swim, or scuba to this event -- but ya can swim at the beach afterward if you like.
Walk from given parking is about 1.2 miles, part of recommended 2.5 mile loop on the mostly-flat Wilder bluffs. Terrain is rated 3.0 for short steep descent into the sandy cove, plus the added adventure. NOTE updated terrain to T3.5; the bluff descent is in fine shape with naturally eroded "steps" but the cave entrance is harder than I recollected: way more obstructed with washed-in piles of tree trunks to climb over and low ceiling to crouch under. No spelunking equipment needed, but still ... grody and difficult enough.
Excessive rain the day before or the day of this event will reschedute. Ordinary coastal fog, wind, light drizzle will not reschedule. Hope for nice warm sun!