Wow, I'm jealous. Glad you're having a good time!
They are some really nice images! Do you have a local crabologist who can give you the species etc? In making that comment I recall the National Museum of Tanzania which proudly displayed some examples of 'ghost craps". This has entered our family folklore, with regrets that I can't remember the Kiswahili names.Martin
I'll get back to you after I speak with my local crabologist, this weekend.
It is called a Ghost Crab. You can read all about it at this site: http://exploreexuma.com/2010/10/22/ghost-crabs/