to check your water tight suff with out power to see if it leaks . and if it dose just let it dry . and its all good ?
Most electronic stuff doesn't like getting wet, so testing without power is a good idea. However, the real danger to electronics is that water takes a while to evaporate, and in that time, your electronics can rust. If your electronics rust, then it's all over. So go ahead and test without power, but be prepared to rapidly disassemble your water-tight stuff and dunk it in rubbing alcohol to dry it.
As long as the magic genie isn't released, you'll be fine. I had a ultra small HAM receiver get soaked in a swimming pool (pretty much a worst case situation). I let it air dry, cleaned it with Corrosion X and a toothbrush, and it's been working with no issues 8 years later. A water tight box can be counted on to leak at some point (USS Scorpion would be a good example). Just be prepared to rehabilitate your equipment when it happens.
