If all you are doing is recreational depths, try out one of the Pelican Micro cases, like the 1050 Micro case.
I know, I know, it's not marketed as depth rated. We've had them to 100'+ often in testing; they stay dry and have been good for quick housings for experimental instruments for us.
The flat lid does bow in by about 1/8" or so, but they haven't crushed yet. If you get the clear plastic model, it's good peace of mind, since you can see inside.
At least give it a try before plunking down the $ for a SPOT. At $14 it's a cheap tryout.
All the best, James