Boat kits section: we have a large selection of monohull kits, mainly in the trailerable range from 4m to 8m. the power cat range extends from 5.2m to 13m.. We have the best range of professionally designed steel, aluminium and timber plans available. sport, dive, fishing or cruising designs for recreational or commercial. The oldest business of it’s kind. since our first plans were sold for home boat construction in 1938, more than 100,000 hartley boats.