Oh, I've never heard that people can swim with whale shark before, so it is rather difficult for me to imagine how to swim with such a huge thing. (I guess maybe I have ever seen people swimming with dolphins on TV. )
I must say that I read the blog very slowly since I am so strange to this kind of field. And there are quite a few of new words for me such as the special terms about boat: port and starboard, etc. However, it seems as if I had followed you to snorkel under the water and even swim for dear life! Oh, so exciting but full of challenges! I love your description :

As they idly zigzagged through the midday sun, caressed by the warm waters of the Caribbean Sea it struck me that this was an all-inclusive whale shark party going on right here and I felt privileged to be a part of it!

I want to tell you that I feel very happy to experience the snorkle with Whale Shark vicariously through you, although I am a little scared.

Thank you for your vivid writing --the bread of spirit so much.