[ironlionzion]

Also, the little film canister is filled with rice which apparently helps dry up any moisture in the box to prevent the port from fogging. So far, it seems to have helped.

[JimJohnson]

At the risk of sounding rude, may I make a suggestion? Leave the camera out of the box, put a single layer of tissue inside the box next to the seal (cut a facial tissue into strips), and seal the box as you would before a surfing run. Find a pool with a dive tank about 5m (15ft) deep - a pretty standard depth. Either have a scuba diver take the box to the bottom, or tie a fairly heavy weight to the handle along with a long cord (like 7m or more). Send that box to the bottom and just let it sit there for say 20 minutes.

5m is 1.5 atmospheres of pressure. If it leaks in this test, I would NOT trust it on a surfing run. When you bring the box to the surface, dry the exterior then open it and examine the tissue. It should be easy to determine if there have been any leaks.

[ironlionzion]

Good idea, I put it in my pool at about 8 ft for an hour without leaks. I'll try to find a pool 15ft deep or more to test it out. I may just go freediving with it and bring it down to 30 ft for 30 sec to test it.

[JimJohnson]

Yeah, I've seen the waves off Oahu. There can easily be a 15 ft difference between trough and crest. Anything going through that will experience a near instant significant change in pressure. By the way, the pressure increases the equivalent of the entire weight of our atmosphere for each 10m (33 ft) of water depth. Therefore, 15 ft is about 1.5X surface. 33 ft is 2X. Water won't compress, but air sure does. At 33 ft, air will occupy 1/4 the volume as at the surface. Given that your box is still mostly air (foam is mostly air), I think you can see why I am concerned. I'm sure you have squezzed a tennis ball in your hand? At 99 feet (4 atmospheres) a tennis ball will be crushed nearly flat.