Playa Carr on the Mayan Sun Coast is a great area. Clean beaches, no sea grass and safe. Only trouble is its in Mexico 40 miles south of cancun. We discovered if your wanting a vacation for playing on the beach and swimming thats the place to go. We have been there twice and thought Ambergris Caye would be the same. Not! We covered the beaches from the dump on the southern end of the Island to the North end of San Pedro. It was all full of sea grass.
One thing that I can say we did like was a snorkel trip with Lil Al. He seems to me nice and honest man. The people on Ambergris Caye was very nice and a good place to eat is the Hideaway Hotel. I hope your stay is a good one.

My experience was, after snorkeling, I did not find the need to swim more, that day.
The beach of Ramon's is free of sea grass and good for swimming.

seems to be some confusion here. On Ambergris Caye the dump is located on the back (west) side far away from any sort of beach. Did you checkout the reef side of the island? Most docks are nice to swim from as the grass is cleared around them and the water is up to 6' deep at the end.
Most visitors to Ambergris Caye are attracted by the reef and excellent diving and snorkling there. That reef protects the shore from wave action and allows the grassy environment which is a nursery for much of the sea life here.

Jesse,

It sounds to me like he didn't have a very good time on the beaches. On the other hand, the circumstances of AC's beaches, and the reasons therefore, are not exactly state secrets.

We've had no time to worry about the sea grass, been too busy trying to figure out what the blue stains were in the sand south of Coconuts. Very untidy.