Formulas and recommendations presented below are based on statistics and research performed by AMD if not specified otherwise. Design approaches From design practice, major considerations affecting selection of characteristics of planing craft are: Layout (in terms of areas and volumes) - for accommodation and functioning of passengers, crew, personnel and equipment; Weights, including lightship weight and deadweight components; Performance - maximum or cruising speed for given sea states and load conditions; Range or endurance - ability to travel certain distance at certain speed; Seakeeping - level of vertical accelerations at desired sea state and speed, with respect to physical conditions of people and functioning of equipment; Construction costs. Factors above are primary ones in defining craft's dimensions at early design stages, while other factors can be clarified on later stages. Most of high-speed craft follow the philosophy of'equivalent safety'; this means safety is provided by craft's limited range and ability to promptly reach shelter that allows sacrificing some of its qualities. For instance, intact stability is being assessed in more charitable conditions compared to seagoing vessels and usually presents no problem on later design stages excerpt for unusually narrow or tall craft.