Other modern features are carbon fibre prods (bowsprits) supported by bob stays, dolphin strikers and bow struts. This enabled quicker setting and dropping of the large downwind sails. Huge spinnakers could be set quickly by having halyards geared by mini blocks running internally in the mast. Dacron sails were replaced by much lighter stiffer less porous material such as mylar plastic. Weights of the bare hulls dropped quickly when New Zealand designer Bruce Farr, using his experience in Moth and Cherub designs used thin 3mm ply supported by multiple lightweight stringers and stiffened with tissue fibreglass. These were quickly followed by foam and fibreglass hulls first designed by Russell Bowler. Bare hulls weigh 120 lbs but are very strong with the use of carbon and kevlar to locally reinforce mast steps, centreboard cases, chain plates and wing attachment points. Rudders were placed 500mm aft of the hull to give more control in extreme planing conditions when only the last few feet of the hull was in contact with the water. With very wide tube and net decks up to 29 feet wide modern boats can carry very large powerful square-headed mainsails that have the controls to twist the head of the main in gusts to de-power. Flying 18 footers can now regularly exceed the actual wind speed when planing on all points of sailing.