Skaerbaek, Denmark, 20110411: EXTREME CHALLENGER - first day of rigging up the Extreme 40 at Skaerbaek Harbour. Polishing and setting up the boat for the first time is not easy. The new Danish Extreme Sailing Series boat is owned by former America's Cup sailors Jes Gram-Hansen and Rasmus Kostner. Photo: Mick Anderson/SailingPIX. Keywords: Sailing, boat, maintaince, catamaran.