While P2i describes its invisible "hydrophobic layer" as covering the exterior and interior of a product, HzO touts what it calls "WaterBlock" technology, which is applied to the internal circuitry of a device to protect it from moisture.
How mainstream water-resistant features become will likely depend on demand, said CNET's Reardon.
"Some of these fringe guys, like Kyocera and Sony, are seeing an opportunity that the average consumer wants some of those features, too. You can see it because of the massive market for cases and accessories to keep these devices shock-proof and also water-resistant," Reardon said.
The real question, she said, is whether we'll start to see top manufacturers such as Apple adding the feature to their products.
"I'm not sure if we're going to see that immediately," Reardon said, "but it wouldn't surprise me if in a couple of years this became a more standard feature on devices."
In the meantime, there's always that low-tech fix if your beloved device has gone for an unplanned swim: Find a bowl and pick up a bag of rice.