Kelty Cloud Pack
Today's backpacks have lightened up like the gear they carry. But unlike a previous generation of wimpy haulers that sacrificed durability for the sake of shaving ounces, the best can be ridiculously tough. Case in point: the Potterfield-endorsed 5,250-cubic-inch Cloud ($750). "The Kelty pack is the best combination of strength and weight there is," he says. "The Spectra-cord fabric—making the pack white because it won't accept color dye—is insanely strong, yet the whole pack weighs less than three pounds." This fabric, originally created for military use, is ounce for ounce stronger than steel but only a fraction of the weight of cloth used in traditional nylon packs. "The suspension system is simple and very adjustable, and an assortment of modular pockets and features can be removed or attached depending on circumstances," Potterfield adds. Sure, the limited edition pack is ultra-expensive, but for high-altitude mountaineering and month-long expeditions where every ounce counts, the Cloud hovers at or near the top of packs for the job. "For its size, strength, and durability, nothing else in my experience can match it." Contact 800-423-2320; www.kelty.com

SmartWool Versa Zip-T
Adaptability and versatility are expedition MOs when it comes to clothing selections. That's why Potterfield favors the Versa Zip-T ($80), part of SmartWool's aptly named Versa-Wear collection of 100-percent merino wool layering pieces. These simultaneously help regulate body temperatures in wet, cold, and dry conditions where aerobic effort equals sweat. "In South Georgia, we skied up to ten hours per day, mostly uphill," recalls Potterfield, "yet the Versa Zip kept me from getting clammy despite the sweaty effort and precipitation." That's because merino wool is extremely efficient at wicking moisture away from the skin, and it creates a micro-layer of insulated warm air that enables perspiration to vaporize away, keeping the skin dry. "The zipper was wonderful in terms of regulating body temperature: down for full-tilt (uphill) boogie, then up at rest stops when the insulating layers came on," Potterfield adds. Contact 800-550-WOOL; www.smartwool.com

GoLite Phantom Jacket and Coal Parka
The beauty of modern lightweight gear is that you can afford to pack a couple extra layers and still cheat the weight scales. Case in point are GoLite's Phantom Jacket ($229) and Coal Parka ($149), wispy warmth-without-weight creations that proved their mettle during Potterfield's Shackleton redux. "I'd use the Phantom while on the move. Over WindStopper fleece, it was enough to keep the howling Antarctic winds and blowing snow at bay, despite its absurdly light weight for a full-on shell," he explains. The Phantom, at just 12 ounces, features a waterproof-breathable Gore-Tex PacLite laminate, taped seams, and an adjustable hood. "At rest stops and in camps, I'd pull on the Coal Parka, one of the most phenomenal pieces of outerwear I've seen in 30 years of wilderness travel. It's warm and weatherproof, yet light." The Coal follows Ray Jardine's lightweight mantra, using airy Polarguard Delta insulation topped by a weatherized Pertex shell fabric. Further insulation value is bestowed by a draft flap, snap-off hood, and dual torso draw cords. Contact 888-546-5483; www.golite.com

Kelty Quasar 0-Degree Sleeping Bag
Fact: Down is useless when wet. While that will never change, down sleeping bags cloaked in waterproof-breathable shells, like the Quasar 0 ($350), are infinitely more trustworthy when bad weather rears. "South Georgia really called for a synthetic bag, but I didn't want to pack the extra weight and bulk," Potterfield says. "The solution came with the Quasar, a highly technical down bag with 750-fill covered in a waterproof-breathable polyester fabric shell." Trapezoid baffles (designed to maintain the down's loft in areas where it may shift and leave cold spots), draft tube and baffle collar, three-dimensional sculpted hood, and sleeping pad security hoops all add up to incredible warmth, even in damp conditions. "Most down bags wouldn't hold up to the wetness of South Georgia, but the Quasar performed flawlessly. At under 3.5 pounds, I saved at least a pound over comparable synthetic sleeping bags." Contact 800-423-2320; www.kelty.com