Crash13..........
I use a C&F Waterproof box model CF-3566.
They sound like they are pricy but once in Belize I had one fly out of the boat as we were going full bore. (Stupid me had it on the seat next to mine.)
We turned around and it took us ten minutes to find it floating in the water.
Considering that it contained about 60 Clousers or approximately $120.00 worth of flies, I consider them worth the price.
They also greatly inhibit corrosion by sealing out saltwater.
You can often find them on eBay for much less than MSRP.