David,
Surprisingly, I never actually made it to the beach. I saw it when I made the trip to Cartagena, and the sand looked fine, white, and gorgeous, but I never made it there. Photos I saw of the beach to the north looked nice, but the water isn't very close to Baq. I stayed near the beach for a few days (at Jamie's beach house) and even thought of going to check it out, but I was too busy socializing to go there. It would have made for a romantic walk after dinner I imagine. Unfortunately, I didn't have a need for it.
Others may have different opinions, but I think the primary reason to go to Baq is Latin Wife. It's otherwise not much of a city. The people are nice, but aesthetically it's lacking quite a bit.
But the water's warm I'm sure. I hope you find someone to go in with.