I just purchased a Canon A570IS, Canon housing and INON D2000s strobe. I have been reading instructions I am wondering what a good starting point would be. Should I shoot AV, TV or manual? If I shoot manual, do I need to add the magnet to the strobe and shoot it manual as well? I have a trip coming up next week and am getting excited to play in the water with the camera. Unfortunately I have not had much time to use the camera on land to try all the options.