Very rough scale with respect to sailing vessels around 30-55 foot length... multihulls (fast = 20 knots, common = 15 knots, many = 10 knots), monohulls (fast = 12 knots, common = 8-10 knots, many = 6-8 knots). For an ocean-going trimaran, their 10 knot speed is not fast. It is quite likely the vessel's apparently near-fixed "wingsail" represents a very conservatively-rigged configuration that is biased for stability instead of speed.