The iPhone 7 is rated IP67. The S7 is rated IP68. On paper, the S7 should fare better at being dunked under water than the iPhone 7.
Yet if you watch the video linked above, the end result is that the iPhone 7 can actually survive up to 35ft immersion in water (albeit without a little damage), while the S7 craps out completely.
I guess specs really aren't everything. Interesting that Apple is actually being very conservative about a key selling point of their flagship product here. Guess they don't want another "-gate" incident on their hands.
If you are still hurting over the loss of the headphone jack, know that it died for a very noble cause.