Otterbox depth testing

[Bowzer]

Making a few UW lights and decided to try a Otterbox 9000 (as per Dive Light - Diy underwater canister scuba torch. . BTW, the Geni works as advertized.) for one.

I put one of the boxes to the test in a pressure pot ( I was looking for the point of leakage, not destruction.) These are the results:

I brought up the pressure gradually at 70PSI ( 161 feet fresh water,156 FSW ,49 meters fresh water, 47.5 meters salt water) there was a small pop. The curved (opposite belt loop) sidewall was visible bowed in.
At about 85 PSI (198 feet fresh water, 192 FSW, 56 meters fresh water, 54.4 meters/fresh water/) there was another small pop.
Same at 100 PSI (230 feet fresh water, 223 FSW, 70 meters/fresh water, 67.8 meters salt water)

I stopped it at about 103 PSI () about 2 minutes later there was a louder pop and the water level in the pot dropped - Failure

I had assumed that the failure would be water leaking past the seal, rather it was catastrophic. about 1/4 of the internal "o" ring support in the top curved side was gone, about 1cm on each side bent inward and about 1.5 cm or gasket was torn out. The latch was also jammed, requiring a screwdriver to be used to lever it open.

From this I would infer that 150 feet. 45 meters is about the maximum one should consider taking this box and that normal recreational limits are probably a safer choice.

 

[reefduffer]

I use one of these (the 1000, for cash and cards) and have no leaks in 40+ dives, a half dozen or so > 90 ft. I appreciate the data point, thanks for taking the time to post. Please add any additional results you might obtain. There was a recent query thread about what to use for this purpose, one person reported multiple failures at 45 FSW, others had the same experience as mine:
http://www.scubaboard.com/forums/accessories/278546-waterproof-case-money-keys-seacard-etc.html

Recreational limits is all I expect to ever need.

 

[Plug]

Was the box empty or did it have something in it? batteries will significantly change the air volume, which may change your result.

Brendan

 

[the_dragon_no1]

old post, i know. but yeah, did you test with things inside it ?
and how long did you test for ?
could you do some time tests on, 20-30meters ?

 

[Bowzer]

The box was empty as the test was to see what the box would hold in the way of pressure. I didn't run other tests as boxes aren't free so testing to destruction starts to cost real money.

As to whether filling it would have helped. I doubt that taking up air volume would have had much effect as not a lot of deflection was required for the failure so the increased internal air pressure afforded by having a lesser amount of air in it would have been minimal.

Filling it with something might help if it braced the material around the seal but this would require a tight fitting rigid material as:
A - it was well beyond the manufacturers depth rating
B - the failure was in the center of the long side of the seal lip. The lip consists of a groove filled with a soft sealing material on one side and a triangular cross section on the other that squeezes into the gap containing the sealing material. What happened is that at pressure the plastic flowed, opening the seal. Once depth was reached it only required a short time to fail

I didn't do tests at the shallower depths as the object was to see if it would hold well enough for deeper depths with a safety margin. For my purposes it was insufficient. There was deflection at 70 PSI - 45 meters salt. There are a few reports of divers using to case routinely to 40 meters. If this is what you want you may find it ok. The Go Pro video camera case uses a similar seal and is rated to 180 feet but it is a smaller structure and perhaps more rigid. Or you could build something like this as it isn't all that difficult
http://www.adirondackscubaclub.com/Projects/Photos/DVD-DNG-014--78.jpg