We catch the last lift of the day, pause at the summit to admire the view and then glide downhill through perfect Utah powder. At the base of the slope, we see Todd and Allen, fellow Floridians we met the day before. "Want to join us for some drinks?" Todd asks. "We'll have to take a raincheck," my wife Jeanette answers. "We're going for a hot-water soak." "That hot tub'll feel nicer once you're wearing a cocktail or two," Todd notes. "No hot tub," Jeanette says. "We're going diving." "In this weather? Ain't no wetsuit thick enough," Allen proclaims. "We're not wearing wetsuits," I tell them, "or drysuits. We're diving in swimsuits." Todd offers some comments on mental stability, or lack thereof. "What're you, nuts?" "Don't ask. Just ditch the skis and ride with us. You'll love it." And they did. And if you ever get the chance, so will you.Utah's Wasatch Mountains are home to some of North America's favorite ski resorts. Each winter, millions of downhillers flock to Park City, Alta, Snowbird and Deer Valley to experience the region's famous powder snow. As that same snow reverts to a liquid state, meltwater seeps into cracks and fissures that lead deep into mountains' roots. There, some 2 miles below the earth's surface, subterranean rocks heat the mineral-rich waters, which are then forced upward by hydrostatic pressure. East of the Wasatch range lies the Heber Valley, and here the heated snowmelt resurfaces in the form of hot springs. Dissolved minerals come out of solution when the warm waters meet the air, creating beehive-shaped rims around many of the springs. When settlers arrived in the Heber Valley in the mid-1800s, they dubbed these formations hot pots. There are more than 200 of these unique formations scattered across the valley floor - including one of truly gigantic proportions. While most of the hot pots measured a few feet in height, the spring on Simon Schneitter's farm bubbled from a gigantic dome some 60 feet tall and more than 300 feet across. The mineral-laden water from the hot pot proved too much for some of Schneitter's vegetable crops, but the Swiss-born farmer soon discovered the therapeutic value of a warm soak after a long day of manual labor. As word got around, the neighbors started dropping by to bathe in the medicinal waters, and soon the Schneitter homestead was hosting buggy-loads of visitors from nearby communities. Recognizing a business opportunity, Schneitter gave up farming, built an enclosed swimming pool, piped it full of mineral water and called it Schneitter's Hot Pots - the area's first resort. Visitors to the resort would often climb out of the pool hungry, enticing Schneitter's wife, Fanny, to take to the kitchen. Soon, her dinners were as much an attraction as the mineral baths, and a public dining room was added to the south end of the old family home. Over the next century, Schneitter's Hot Pots evolved into the Homestead resort. Today, the Homestead is a four-diamond vacation property that offers a unique blend of upscale dining and recreational activities combined with picturesque, cottage-style accommodations. In summer, visitors come for golf, horseback riding and mountain sports, while winter brings skiers and snowmobile tourers. The Hot Pot, which is now known as the Homestead Crater, remained one of the resort's major attractions. After Schneitter tapped into the crater at ground level, mineral water no longer spilled over the top, and the water level inside dropped some 40 feet. For years, guests could climb the walls of the crater to peer into the dark interior, but could sample the water only in the adjoining mineral baths. Then, in 1996, an enterprising diver with a truckload of high explosives brought hot water soaks to a whole new level.THE DIVE SHOP IN THE ROCK Divers in central Utah knew of the Homestead Crater, but only a handful of search-and-rescue types had ever sought permission to free-rappel into the crater's interior. Provo resident Jerry Simons knew there had to be an easier way to get divers into the crater - easier, at least, for the divers. For Simons, creating that easy diving access required the negotiation of a long-term lease of diving rights from the Homestead Resort, two years worth of engineering details and 15 tons of dynamite. At a cost of more than a quarter-million dollars, Simons' crew tunneled through the north wall of the crater to construct water-level access to the hot springs and the world's only underground dive shop. When the diggers reached the crater's interior chamber, they found a pool of blue water some 85 feet across and 65 feet deep. Simons installed topside and underwater floodlights, constructed a floating access platform and added an underwater platform at depth of 22 feet for checkout dives. On July 1996, the Homestead Crater dive operation was opened for business, and was soon busier than Simons anticipated. Shops in Provo and Salt Lake scheduled training dives in the protected, year-round warmth of the crater, while an increasing number of visiting skiers and vacationers from across the country dropped by to sample one of the world's more unique diving venues. Simons instituted rules to prevent divers from disturbing the fine silt on the floor of the crater, and he and his sons, Jim and Craig, sponsored an ongoing underwater archaeological survey of the crater's contents. To date, they have unearthed Native American artifacts, numerous old coins, a pre-1900s revolver and shotgun, and a vintage wagon wheel, which is now suspended at a depth of 30 feet, where it can be viewed by divers.DIVING THE CRATER It is the first week of February, and we are to meet Simons at the double steel doors that lead into the crater's interior. The crisp winter sunshine has minimal effect on the 3-foot layer of snow covering the crater's cone, and outside temperatures hover around the 20-degree mark. Entering the tunnel, we are enveloped in a swirling cloud of mist - the result of the cool mountain air meeting with the interior's 96-degree water. Passing the rock alcove that houses the dive shop counter, we descend a short ramp to the floating deck. Simons turns on the underwater floodlights, revealing a deep blue patch of water that fades into the surrounding mist. In summer, he tells us, when air temperatures are higher, the mist dissipates and the crater is lit by a spectacular shaft of midday sunlight. Today, we will rely on the artificial illumination and our dive lights. As we gear up, Simons runs through a list of the crater's vital statistics. The basin is located at an elevation of 6,000 feet, is believed to be about 10,000 years old, holds approximately 560,000 gallons of 96-degree water and is fed by a 200-gallon-a-minute natural spring, he says. The water contains high levels of carbon dioxide, boron and calcium carbonate, and no, the suspended minerals are not hard on the regulators or other dive equipment. Simons, whose eclectic background includes doctorates in both psychology and electrical engineering, tells us that the specific gravity of the crater's water is actually less than one. For those of us who forgot high school chemistry, that means a diver can shed a few pounds from the weight belt - an average of 5 pounds less than would normally be needed in fresh water. We slip off the platform into water that's near body temperature. Underwater, the vis is better than in the mist-filled crater - about 50 feet. We begin a slow spiraling descent, investigating the cracks and crevices of the walls, then pausing to mug for a photo at the suspended wagon wheel. To fully appreciate the crater's flooded interior, we slow our swim pace and focus on the geological formations and patterns. There are no pretty fish to chase, no waving sea fans, but we still manage to spend an enjoyable half-hour touring the basin. After surfacing, we lounge on floating benches for another hour and are joined by resort guests who venture into the crater to snorkel or just soak in the warm water.ONE FOR THE LOG BOOK We spend the next four days at the Homestead, dividing our time between area ski resorts and backcountry snowmobile tours. Each winter adventure ends with a dive or a snorkel in the crater, which we have decided is far superior to the more traditional apres-ski hot tub. One evening, while floating in the crater with a group from California, we are asked why Floridians would come all the way to Utah to scuba dive. "Actually, we came for the winter sports," I admit, "but it was the opening of the crater that swayed us from our usual Colorado destination. To the best of my knowledge, there's no other place in the world where divers can park the snow skis, slip off the parkas, gear up in a man-made cave and dive into a giant natural hot tub," I tell them. "The chance to add this unique dive to our log books was an opportunity we just couldn't pass up."