I wanted to point out here one possibility that has not yet turned up in the reviews so far.

I took an afternoon snorkeling excursion from Placensia to the Laughing Bird Caye. The excursion took about 3.5 hours, including a 35 minute choppy boat ride, a short stay on the tiny island and a round of snorkeling and came at a cost of 85 USD.

When our small tour group of three arrived at the tiny island, it was very busy with a big boat moored nearby. It was a strange contrast with the quiet beach in Placensia where we arrived from.

I saw a few corals and fishes during the snorkeling but visibility was not great and the quality of the corals didn't seem amazing either to my unexperienced eyes.

I would not pretend to have really appreciated the site as a whole by this short visit but after considering and pondering for a long time on all the possibilities and options, this came out as the least worst option to me.

In Placensia, also a tour to Glovers Reef was advertised at USD 125 but that tour company did not seem very motivated when I asked for more information so I gave this one a miss.