In 2017 we can expect almost every flagship smartphone to be water-resistance to some level. While many don't think this is important, the peace of mind is very refreshing. Knowing that if the phone gets wet, or dropped in the pool (or toilet) it will continue to work.
Samsung's Galaxy S7 is IP68 dust and water resistant. That means it can be in roughly 5ft of water for over 30 minutes and work fine. Many have tested it deeper and longer, with no problems. Expect the Galaxy S8 to remain IP68 dust and water resistant. A favorite feature of mine.
For a comparison, the iPhone 7 is only IP67-rated. Meaning it can't go very deep or be in water very long. It's more "splash resistant" that water resistant, which is very important.
If durability and resiliency is important to you in 2017, you know what to buy.