When Apple released its iPhone 6s, 6s Plus and the more recent SE model, the announcements were flooded with new features that set the newest lineup of iPhones apart from their predecessors: faster processors, 3D Touch technology, better cameras, etc. Curiously, what is arguably one of the most valuable features for many iPhone owners was not on any of those lists: All three iPhones are more water resistant than those they replaced. And it appears to have been no accident.

Improved internals
It didn't take long for technology teardown sites like iFixit to open up the new handsets after they were made available to the public. When peeking under the hood of the 6s series, they quickly discovered a new adhesive lining that appeared to create a seal around the display. With the iPhone already held together by screws, they hypothesized the new substance could be there not to hold things in place, but to keep certain elements (like liquids) out.

Further exploration showed the phones' internals similarly safeguarded against liquids, with the phones' most fragile connectors insulated by "tiny silicone seals." While the devices were still by no means fully waterproofed — the Lightening port, headphone jack and speakers could still let water in — they appeared to be far more durable than previous handsets when it came to getting wet. 

Taking a look at this year's release, the iPhone SE, iFixit again found foam silicone seals around otherwise-vulnerable connectors for parts like the front camera, volume controls and rear camera. There were still plenty of parts that were not protected, however. And, the adhesive seal found running along the border of the 6s models was notably absent from the SE, suggesting it could have been included to enable 3D Touch, not for waterproofing. Still, the SE appeared far more water-resistant than the 5s model it replaced. 

Putting them to the test
Before long, YouTube reviewers began testing just how well this improved design stood up to water. In one video, YouTube user Zach Straley placed an iPhone 6s and 6s Plus each into a shallow bowl of water, then waited as their timers ran. Both survived 30 minutes before Straley removed them from their liquid laboratories apparently unscathed, with the displays and 3D Touch functionalities working as expected. 

While this "test" does not guarantee that nothing went wrong internally, or that the iPhone would be able to withstand any more than a few inches of water, it does suggest the handset is more durable than previous models. For example, in another of Straley's videos, an iPhone 5s starts having problems with the display after just a few minutes submerged in water, and eventually ceases working altogether after about 5 minutes and 30 seconds. 

Interestingly, the iPhone SE does not fare as well as the 6s. In Straley's video, the phone appears fine until about the 20 minute mark, when it eventually powers off. Again, this does not mean there was nothing going wrong inside the phone before this point, but its ability to survive nearly four times as long underwater as the 5s indicates considerable improvement. 

The bottom line
iPhone owners have been asking for a waterproof phone for years, and their cries have only gotten louder alongside Samsung's release of the water-resistant GS7. While the iPhone 6s, 6s Plus and SE are by no means there yet, they are considerably more forgiving when it comes to splashes and spills than any Apple handsets that came before them. Rumors and recent patents do suggest Apple could be aiming to make its next smartphone fully waterproof, but in the meantime, splash-proof will have to do.