The Bat Cave is an awesome dive. HOWEVER you must pick the right time to try it out as if it is not completely calm you will be dashed to peices on the rocks! Best bet is to go with a dive shop as they will be able to advise you. Plus there are some other little caves and swim throughst that are just as pretty that you will miss if you try to do this dive by your self!

Take a look at  http://youtube.com/watch?v=gm853e2HQR0 for a great video of the dive!