A 3.60m "flat-cat" built primarily to investigate methods and materials in the ongoing effort to market types that will run upon a single ski. This prototype has been relocated to a test-site where powered runs and tow-trials will be undertaken to determine the outline of planing-surfaces for fitment to mono-ski types that will be adapted to outboards, water-jets and aero-engines. The weight of its structure compared to mono-skis is excessive, although still lighter than conventional hulls of the same length. This craft can be lifted by a single operator and balances around the forward edge of decks that are 60/40 centimetres wide (though a 50/50 split would make it easier to carry). This asymmetry was designed to allow for an operator sat sideways in control of a conventional tiller. The skis are formed of seven-inch timbers planed to 12mm (half-inch) thickness and supported by spray-laminated 50 mm (two-inch) thick PET foam of a density around 50 kilos per cubic metre. These are supported by an "H" frame made of a half-dozen PAR four-by-two inch whitewood (hence the weight) which results in a craft around twelve feet long by four wide. This of course would require trailering, whilst the smallest variations of mono-skis can be roof-racked for transport so that a 10 or 15 HP two-stroke motor can be carried separately in the boot, or trunk.