Speedlite 430ex Ii External Flash
What is a good waterproof case for a digital SLR camera?

I am looking into underwater photography to broaden the spectrum a little more .. or take pictures in the rain. What are some good (even some that allow an external flash or something, of course, I'm not sure if there is such thing), not bad in the humidity (I will probably buy some of the gels to prevent that), and are very durable … lasts a long time is an advantage. I'm graduating this summer, so do not have a budget (money grad). PS I have a Canon Rebel XSi and have a Speedlite 430EX II

might consider this http://www.amazon.com/gp/product/B001CP0IBS?ie=UTF8&tag=bestdeals-y-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=B001CP0IBS

Speedlite 430ex Ii External Flash

Is a Canon Speedlite 430EX II external flash is used in a Canon Rebel XTi?

If the flash can be used without problems

CANON SPEEDLITE 430 EX II FLASH