Large Rolling Backpack I'm Going To Asia...need Some Tips/advice?

I'm going to Asia...need some tips/advice? - large rolling backpack

I am in Asia for 3 weeks ... This question has several components:

1 - I go to Bangkok, Ko Samet, Phuket, Singapore and the Philippines (in that order) ... What kind of luggage should I bring? I intend to 1 Rolling attract large / long pocket, but then I thought about just one of those big backpacking North Face. What do you suggest? Note that I take the ferries, ships, airplanes, taxis, etc.

2 - When I, I relied on the beach where I can hold my camera / ID / money for sure (water, sand, and thieves)? I want to keep near me, but I want the freedom to go in the water for several minutes, then back to my towel and suspend, then back to water, etc. Even when I was in all Snorkeling / Diving trips, where you can I have my things to stay safe (thieves) and dry?