Hydro Lance Fast Ship Technology Brief All Hydro-Lance vessels are simple displacement hulls, with the same math calculations used for weight displacement of a rowboat, or a full sized cargo ship. However, because conventional ships require significant freeboard (that distance from the water's surface to the top of the hull) to prevent crashing waves from rolling over the deck, the tonnage of ship displacement often far exceeds the intended use. For example, the cruise ship Stattendam is a 55,451 metric ton vessel and will carry 1,266 passengers plus a crew of 704; that's 28 tons of ship for every person! The Hydro-Lance does not utilize but a very few feet of freeboard and therefore a 2,000 metric ton ship may more efficiently accommodate the same mission; one 2,000 gross metric ton Hydro-Lance vessel will carry a net cargo of, at least, 1,000 metric tons, having a significantly higher volume of usable space due to entirely different construction geometry.