I was skeptical. So I stuffed a paper towel into this bag, crammed the bag into a small pocket and took it to 43 feet while on a 2 hour drive. The paper towel was Absolutely dry at the end. So, I shoved an extra phone AT&T sent me, for no apparent reason, into this bag. The phone worked through this bag as it unlocked with facial recognition.
I beach dive a mile from shore with a DPV and no surface support- Solo. So, basically the Nautilus rescue beacon and my Garmin inReach mini are just there as "two is one and one is none. Not sure what three is. But now I do have three ways for coms due to this damn fine bag.