As much as I don't want to share this secret spot I must say a few words about it, firstly it's really a windsurfing and paddle boarding SUP spot, it's actually a good launching spot for kiteboarding to go out to the ocean, but the lagoon isn't big enough to cruise around in. Secondly, I have snorkeled there but there's not much to see below. Thirdly, Swimming isn't that great either because it's just not deep enough in low tide. Best swimming and sunbathing beach is Concha.
Lastly, and most importantly. If you do come to enjoy Playa El Rio and I hope you do, please do a beach garbage sweep. I find it an honor to enjoy this remote spot. So I personally take a few minutes to remove garage about a 10 meter diamater from straws, to cigarette butts, plastic...ect. Hope to see you there and if you do please stop by and say Hello!