One of the big trends in smartphone technology right now is adding water resistance to the handsets, something Apple has yet to do. When management unveiled the iPhone 6S and 6 S Plus earlier this month, they didn’t say anything at all about water resistance. Of course this is probably because Apple has not yet perfected the capability in its iPhone, although the company appears to be heading in this direction.

In fact, the folks at ifixit found signs that the iPhone 6S plus might be water resistant in some parts, although not in all of them.

iPhone 6S Is Somewhat Waterproof [REPORT]

iPhone 6S has mystery adhesive

They published their teardown of the iPhone 6S earlier, and one thing they noticed was a “strip of sticky goop” in the phone. Apple doesn’t typically do things to its devices without a very good reason, and the ifixit folks weren’t able to see any obvious reason for the adhesive they found. The iPhone 6S’ display was held in by screws, so clearly the adhesive wasn’t there to secure the display. After all, the displays in past iPhone models were rather difficult to remove.

So why would Apple include it? Ifixit suggests that the goo serves as a sort of gasket to help keep water out of some parts of the iPhone 6S. Some iPhone 6S users decided to take a risk and submerge their phones in water, and while not all the iPhones survived, some did, which appeared to support ifixit’s theory.

As a result, they decided to tear down the iPhone 6S again to look for more evidence that Apple was targeting water resistance with that mysterious goo.

Clues from Apple’s patent filings

The tech community always keeps a close eye on the patents Apple files, and apparently there have been some pertaining to water resistance and/ or waterproofing. The patents stretch back over the last several years at least. According to ifixit, Apple has not succeeded in totally incorporating the patented technology into the iPhone 6S, but it looks like the company might have made progress.

They noticed that the strip of goo wasn’t merely run around the display like caulk on a bathtub but rather that it “has been subtly reworked to accommodate the new gasket.” They saw a very slight increase in the width of the lip that goes around the frame of the iPhone. That slight increase was just enough to put the gasket on.

Other signs of water resistance in the iPhone 6S

In addition to the apparent gasket around the display, ifixit found tiny seals made of silicon around all of the cable connectors on the iPhone 6S’ logic board. They noted that the connectors are the most likely components to be damaged by water and that Apple actually filed a patent for something just like this earlier this year.

As a result, they concluded that the company has successfully incorporated one part of the tech described in that patent in the iPhone 6S. The same patent also described a “hydrophobic conformal coating for printed circuit boards,” reports ifixit, but they’re still testing the iPhone 6S to determine whether Apple has also managed to work this technology into the phone.

Still some vulnerable parts on iPhone 6S

They didn’t see any significant “waterproofiness” changes in the rest of the iPhone 6S. For example, the volume and power buttons, the speaker, the SIM tray, and the headphone jack don’t have any signs of added water-resistant technology. Ifixit suggests that next year’s iPhone 7 could be fully waterproof by adding further changes, and recent rumors back up this speculation.