I've read posts before about people conveting MTE or aurora or whatever DX / KD lights into dive torches, but am at a loss for search terms.
I'm thinking depth proofing an 18650 Aurora P7, but general points may be helpful as well.
Ideas so far:
-Need to upgrade lens, O-rings
-heatshrink around body, covering bezel / tail-cap joints. Like a condom for the battery tube, should prevent water ingress
-convert to twisty / solid tailcap - avoid obvious weakness clicky switch boot: this may alter the project and force me to go with a solarforce L2 as I know solid tailcaps are P / C series compatable option.