1. with the fisheye lens .... make sure your hands [and every OTHER body part ] are BEHIND the camera
2. get in close
3. everything looks smaller / further away in photos , than it actually WAS ...so , waves under head high [unless you are deep] look very average
4 most importantly...
have FUN !!!
and , USE it ...LOTS !!
shoot in "burst" mode , and you will have HEAPS of shots to choose from . Or , FILMING mode.
[oh yeah , it doesn't hurt to also spit on the lens from time to time , dip in water , take photo immediately . This helps avoid water droplets wrecking your shots]