Delfins does have a nice beach. I’m not sure where they stole it from, but it’s coral sand. Nice and fine and light. Built up about 4 ft above the waterline with steps down to she coral scree into the water. The swimming area is very nice as well. Mainly flat smooth rock bottom
What's described here brings up an important question; what is the beach desired for?
Years ago staying at Eden Beach Resort there was a man-made 'beach' - and if you just wanted to lay in a lounge chair and sun on it, fine. But if you walked to the water, you saw the sand ended and there was a rocky stretch that waves washed over, then an abrupt 'step' of at least a few feet.
My point is, if 'beach' to you means a gradual sandy slope out into the water, where people wade out to waist-deep and frolic in the water (e.g.: swim, snorkel, float on an inner tube), that is not your beach.
Sand Dollar Condo.s has a small beach by the pier there, with a cordoned off swim area, which would be okay for some uses (e.g.: a couple of little kids who wanted to play in the sand, or a pair of adults looking to sunbathe) - but if 'beach' to you means long, romantic walks on the beach, nope, not gonna do it.
I believe Harbor Village has beach, I don't know about AI, and every time I look at their prices I quit researching.
Did you consider Curacao? The A.I. resort is Sunscapes Curacao, where the last Scuba Board Surge was held Jan. 2019. A couple of links may be helpful:
Curacao Trip Research Notes
Curacao Trip Report with SB Surge Jan. 2019