What To Look For
So called shaped, or parabolic skis, became popular in the early 2000s because their sharp sidecut, which gives the skis a distinctive hourglass shape, makes turning and getting the ski on edge far easier than older, straight skis. Parabolic skis also can be made shorter because their shape gives them more surface area than traditional skis.
Whereas parabolic skis have a traditional camber, with a slight arch at the tip and tail and an arch in the middle, modern powder skis embrace rocker to achieve better float. Rocker skis look a lot like a banana, and the technology was borrowed from water skis, where it is common. Rocker is another term for reverse camber, meaning the tip and tail are elevated, but the middle is flat. This reverse camber makes the ski ride up in deep snow, instead of sinking.
When shopping for shaped skis, check the manufacturer's guidelines for weight, which will dictate how long a ski to get. Your flotation in deeper snow will be affected by surface area versus weight. Length is still important, but with shaped skis, you don't use height as the defining method for figuring out what size ski to get.
Reverse camber, or rocker skis, usually have an early tip and tail rise, meaning the ski feels shorter underfoot than its actual length. While this helps with turning, it is not as good when skiing at speed, so you may want to consider a longer ski than a standard parabolic ski when getting a powder board.
With powder boards, it is best to get a wider ski than you might normally want for riding groomers at the resort. Wide skis, which usually range from 110mm to 125mm at the waist, provide more effective float in the steep and deep.
Where To Buy
Given the sheer volume of skis on the market, the best place to shop for a new pair of parabolic or powder boards is at your local specialty ski retailer. Several online retailers, like Backcountry and REI, also stock a good selection of skis (see Resources).
If you live on the East Coast, it may be harder to find a good selection of powder skis, because the snowfall and terrain is better suited to the narrower-waisted parabolic skis.
Powder and parabolic skis range in price from $400 to $800 (2010 prices).
There are many different skis and ski companies on the market. For a good powder board, the Liberty Double Helix ($749, 2010 prices) is a popular option. The Icelantic Shaman ($649, 2010 prices), which has a super-wide tip of 160mm with a deep sidecut waist of 110mm, meaning it turns well even on groomers. Movement's Fly Swatter ($750, 2010 prices) has a super-fat 125mm waist.
Examples of good parabolic skis include the Line Prophet 90 ($675, 2010 prices) and Rossignol Phantom SC80 ($650, 2010 prices).