Most tour operators do not provide secure storage of personal goods. It' a good idea to take a water proof pack. There are a number of products on the market. You want to be sure that what you use is truly water proof. I have successfully used "The Splash Caddy" which is PADI certified. These are available in various sizes. They conveniently attach to your life vest, which most operators require you to wear. If you order, on-line, get a couple extra liners.