Abstract: A strut mounted gear box for counter rotating propellers. The gear box is strut mounted for securement to the hull of a boat. A main input shaft is coupled to a propulsion component of a boat with a distal end secured to an idler gear cage assembly located within the gear box. The main input shaft transfers torque and rotation from the propulsion component to an idler gear cage assembly. An inner tail shaft is coupled to the main input shaft and arranged to rotate the inner tail shaft in a first direction. A counter shaft is coupled to the idler gear cage assembly and arranged to rotate the counter shaft in a second direction. A first propeller is secured to the inner tail shaft providing rotation in the first direction; and a second propeller is secured to the counter shaft allowing rotation in the second direction.

Abstract: A strut mounted gear box for counter rotating propellers. The gear box is strut mounted for securement to the hull of a boat. A main input shaft is coupled to a propulsion component of a boat with a distal end secured to an idler gear cage assembly located within the gear box. The main input shaft transfers torque and rotation from the propulsion component to an idler gear cage assembly. An inner tail shaft is coupled to the main input shaft and arranged to rotate the inner tail shaft in a first direction. A counter shaft is coupled to the idler gear cage assembly and arranged to rotate the counter shaft in a second direction. A first propeller is secured to the inner tail shaft providing rotation in the first direction; and a second propeller is secured to the counter shaft allowing rotation in the second direction.

Abstract: The system is an enclosed, oil filled, shaft and thrust bearing assembly which includes an oil pump to circulate the oil throughout the system. The thrust bearing assembly allows the thrust to be directed to the shafts mounting system rather than through the vessels main propulsion engines and isolators thereby reducing vibration and noise emissions. In addition the elimination of thrust loading transmitted directly to the propulsion engines reduces wear and tear on the engine mounts, isolators and engine support structures. The non rotating casing of the shaft assembly allows clean water to flow to the propeller which allows more delivered horsepower to be used by the propeller.

Abstract: The system is an enclosed, oil filled, shaft and thrust bearing assembly which includes an oil pump to circulate the oil throughout the system. The thrust bearing assembly allows the thrust to be directed to the shafts mounting system rather than through the vessels main propulsion engines and isolators thereby reducing vibration and noise emissions. In addition the elimination of thrust loading transmitted directly to the propulsion engines reduces wear and tear on the engine mounts, isolators and engine support structures. The non rotating casing of the shaft assembly allows clean water to flow to the propeller which allows more delivered horsepower to be used by the propeller.

Abstract: A tunnel-type boat-hull construction is operative with substantially reduced frictional resistance in the water and also with improved high-speed stability. An air-withdrawal port is provided in the bow portion of the tunnel, and exit ports which are interconnected to the withdrawal port are provided along generally downwardly facing submerged surfaces of the hull. When the boat hull is operated in a forward direction, air is captured in the forward portion of the tunnel, and a portion of the air is withdrawn through the withdrawal port and is exited through the exit ports. The air which is exited through the exit ports provides lubrication for the submerged hull surfaces so that the hull is operative with substantially improved efficiency; and because the air is withdrawn from the bow portion of the tunnel, the bow uplift effects which are characteristic of conventional tunnel-hull-type vessels when they have been operated under high-speed conditions are substantially reduced.