Hydraulics & Blue Blood
I'm particularly keen on sea stars:
One minute it's just a laid-back echinoderm pulling around the primordial muck of the oceans, propagating on a lifestyle dating (at least) as far back as the Cambrian. And in the next moment, it has missed its exit and is stuck in a discrete tidal pool, tube feet committed to a stationary position anticipating the return of the tide. That's the best discovery: sea stars in tidal pools. They slowly contract and pull around the water using a network of valves, tubes, and muscle contractions to create a hydraulic system. Their tube feet tickle igniting moments of childlike fits that I'll chalk up to momentarily lapses in Cousteau-in-training curiosity.
That's why I avoid the main strip of Folly Beach. The magical spots occur on the side facing the Morris Island Lighthouse. It's quiet and full of surprises. Beyond sea stars, I've encountered live horseshoe crabs, unintentionally swam next to a small group of rays, and have been under the watchful eyes of a dolphin pod playing a few yards off shore.
This is my favorite part of the Lowcountry. (I also eloped on Folly, which might add to my fondness.)