I strongly urge you not to go with the disposables!!!!! I have lost SO MANY pictures of wonderful experiences. They are for super shallow snorkling. Splurge! Get a great camera and light!

Here is one trick, though, if you just won't learn from the one bit of wisdom I have to share (and skip the disposables):

When you are diving with disposables you may accidentally go too deep. The disposable will quit working. If you ascend enough it will start working again and then you can descend with it again.