Essential Spares for Underwater Photography?

[Chris Ross]

2 hours ago, Dave_Hicks said:

Maybe so if deep enough, thus the cap. Aren't these rated to 300ft? I have seen a few friends diving without the cap by mistake. That is really fun to point out to your buddy at 60feet under! 😧

 

BTW, i had the o-ring go loose on my pressure valve after a number of years. Be sure to check it and replace if it shows wear.

You can calculate the downward force on the button based on the diameter of the stem, assuming it's 5mm dia the force pushing down is around 0.5 kg at 30m.   I would guess there is close to the limit.  There's probably some sciction from the seals on the stem which would help, but it's still a risk diving without the cap.  The o-ring seal for the cap also should be serviced periodically - a touch of o-ring grease will help.