Just tell you on my recent trip to Sipadan, I'm diving with 3 cameras (Nikonos V, III & Cannon S40 digital) & I felt good. The thing is you have to be comfortable in the water & just don't think of anything worse happening to you but just be alert & importantly know your own diving profile. I think you need lots of diving as practise to get yourself closer to the underwater nature but as for now stay off Sipadan as sharks are everywhere & diver like you will definitely feel insecured. Sorry?