iPhone 6s Survives a Puddle But Not a Pool [Video]
Comments

Mu is correct about water penetration being greater/faster as pressure increases but i think the real cause, and reason none of these water submersion tests are worth a damn is because there is no mention of the waters electrical conductivity, if you use good reverse osmosis water it will survive indefinitely (i6s bowl test). Generally pool water is very very conductive, being around 1000-1500 μS/m depending on age. This will kill all powered-up circuit boards quick fast.

As pressure rise the water find its way trough the sim holder. In the cup of watter the presure is lower so the water may not displace the air inside the phone.

The pressure's effect is relatively small for every 10 m of meter the pressure goes up 1 atm. here the water was 4 feet deep that roughly equates to 1 m and hence 1/10 of atmosphere for pressure increase. the water in the pool contains ion that conduct electricity better than the fresh water hence it will most likely short circuit the phone

"do not jump in the water with this thing" JAHAHAHAHAHAHAHA WHO TOLD YOU TO JUMP IN THE WATER WITH THAT THING! Its a non waterproof cellphone not a fokin blue whale