Its an ocean baths (or a pool filled with sea water) for swimming on the right & a rock shelf on the left.
I usually pretty safe, but I always take great care....I went back today & the surf was even bigger so didn't venture out.
The pool is actually empty for maintenance at the moment (its annual sand clean-out...lol) so its OK.
That said, I have seen waves 4-5 feet in the pool itself a couple of times.
Here's the ocean baths on a good day last year. I took the photos I posted yesterday on the small walkway (just near the swimmer)