Goose down is the perfect insulation except for one thing — it loses its ability to insulate when it’s wet. This, of course, you know. It’s why your down bag often becomes worthless on a river trip, why puffies are fine for skiing on cold, dry days but not for dumping conditions, and why synthetic insulation is as popular as it is. Now, in what might be the holy grail of insulation, two separate down companies have developed what they say is hydrophobic down (though not waterproof).

The brand names for these water-hating downs are DownTek, created by a company called Down Decor and used next winter by Brooks Range; and DriDown, exclusive to Sierra Designs for a year and available in sleeping bags June 1. In the U.K., Berghaus also claims hydrophobic down, but doesn’t identify the source.

With DriDown, a micro-polymer coating is applied to the down during the finishing stages, after it’s been washed. It adds no more than ten bucks to the cost of a $300 sleeping bag, doesn’t increase the weight because it’s just a molecule thick, and also resists skin oil.

It works, SD says, seven times longer than untreated down, citing a test in which two 15-degree bags, one with DriDown and one without, were put into a chamber set at a constant, 80 percent humidity for eight hours. The DriDown bag measured 98 percent of its original loft. The standard down bag fell to 70 percent loft, effectively turning it into a 30-degree bag. S.D. says that level of humidity might well occur with the rise of evening dew point or a combination of a snowfall and a tightly battened tent. A further advantage: If you’re out on a multi-day trip with day upon day of high humidity, a typical down bag will get colder because you’re never able to let the condensation from a night’s sleep entirely escape. But because DriDown resists getting as wet in the first place, SD says it’s effectively the same as a 33 percent faster drying time vs. regular down.

SD’s DriDown also promises longer life because it holds its loft better when washed.

Brooks Range’s first DownTek product, the Mojave Jacket, is interesting not only because it uses 800-fill (rather than S.D.’s 600 in the Tov Belay, shown above; UPDATE: S.D. says its Gnar Lite jacket will have 800 fill), but also because it uses Pertex, an extremely lightweight, water-resistant shell fabric.

Also interesting: Down Decor invited representatives from The North Face, Columbia, Mountain Hardware, and Marmot to a suite at the Marriott across from the Salt Palace Convention Center during the most recent Outdoor Retailer trade show in January — unlike DriDown and Sierra Designs, Down Decor has a non-exclusive deal with Brooks Range.

The Sierra Designs five-bag, 600-fill line comes to REI this summer. The range includes the 0-degree Zissou (3 pounds, 1 ounce; $299) up to the 30-degree Eleanor 30 LITE women’s bag (2 pounds, 9 ounces; $259). The two jackets mentioned above will launch in August; the Tov Belay will be $259 and the Gnar Lite will cost $229.

Is hydrophobic down nothing but hype and a new way to sell bags and jackets? Or is it the real deal? There’s only one way to find out, and once we’ve gotten our hands on it to test, we’ll let you know.