Abstract: A boat-shaped sprinkler irrigation machine is adapted for large-scale farm irrigation canals, and includes a hull, a traveling propulsion device, a sprinkler irrigation device, and an electric control device. A sprinkler irrigation auxiliary support mechanism is disposed on the hull, and comprises support legs and support roller groups. The support legs are symmetrically disposed on left and right sides of the hull, and top ends of the support legs are mounted on the hull. The support roller groups are mounted on bottom ends of the support legs. The support roller group comprises support rollers. The sprinkler irrigation device comprises a self-priming pump, a sprinkler frame, and a sprinkler gun. The sprinkler frame is fixedly mounted on the hull in a position corresponding to a symmetrical center of the support legs, and the sprinkler gun is fixedly mounted on the sprinkler frame by means of an adjusting assembly.

Abstract: Methods and arrangements to redirect a forward thrust generated by a propeller of a watercraft to provide a non-forward thrust are disclosed. More specifically, embodiments comprise a control surface to redirect the forward thrust from the propeller. Based upon a position (i.e., distance and orientation) of the control surface with respect to the propeller, the redirection generates the non-forward thrust or thrusts. By redirecting a component of the forward thrust back toward the bow, the net forward or reverse, port or starboard thrusts and rotational thrust can be adjusted in fine increments. For instance, by adjusting the amount of prop wash hitting the control surface, the magnitude of the redirected thrust from the control surface can be adjusted. Further, adjusting the angle of the control surfaces adjusts the direction as well as magnitude of a reverse thrust component. The net thrust can be in any direction and rotational.

Abstract: A propeller drive for boats features a transition cone between the gearbox housing and the propeller hub(s). The propeller hub (that is closest to the gearbox housing) is smaller in cross-sectional dimension than the gearbox housing. The dimension of the front end of the transition cone corresponds to the cross-sectional dimension of the gearbox housing, and the dimension of the rear end of the transition cone corresponds to the cross-section dimension of the (closest) propeller hub. The transition cone has a bulging shoulder between the front and rear ends, the largest peripheral cross-sectional dimension of which is greater than the cross-sectional dimension of the front of the transition cone.

Abstract: A marine vessel and drive combination includes port and starboard tunnels formed in a marine vessel hull raising port and starboard steerable marine propulsion devices to protective positions relative to the keel.

Abstract: A marine vessel and drive combination includes port and starboard tunnels formed in a marine vessel hull raising port and starboard steerable marine propulsion devices to protective positions relative to the keel.

Abstract: A boat hull having a tunnel structure along the bottom of the hull in the form of a truncated hollow partial cone indentation parallel to the keel of the boat. The tunnel has a truncated end attached to the bottom of the hull near the keel and an open end attached to the transom of the boat. The tunnel encloses a propeller shaft extending from the boat interior at the truncated end, the propeller shaft, a propeller and a rudder. The angle of the cone with respect to the keel places the propeller about 45% to 50% within the tunnel at planing attitude or speed. The combination of the tunnel placement along the hull and the axis of the propeller shaft increases the efficiency of the boat and reduces fuel consumption.

Abstract: A hull for a marine propulsion system includes recesses for receiving and protecting propellers of the propulsion systems. The hull may be designed with a pair of recesses, such as in a stern region, in which props of two separate electrically driven propulsion units are positioned. The recesses are formed integrally with the hull shell, and present open lower and aft regions for free circulation of water displaced by the props. The recesses may also properly orient thrust from the props, such as at oblique angles with respect to a centerline of the hull. The recesses may be formed in the hull for receiving the propulsion units as an optional package. A top surface of each recess forms an integral cavitation plate for reducing or eliminating air entrainment into the water stream around the props as well as cavitation due to localized low pressure regions during operation.

Abstract: A steering unit (10) for a barge tow (12). The steering unit (10) has a hull (16) which includes a pair of spaced longitudinally extending portions (50, 52) and defining a cavity or tunnel (54) therebetween. A propeller (48) and rudder (36) are mounted within the cavity (54). Rear flaring side portions (74) define the cavity (54) adjacent the rudder (36) and the rudder (36) is movable between contact positions against opposed side portions (74) for exerting a maximum side thrust.

Abstract: A propeller guard including a cylindrically shaped ring which includes a plurality of evenly spaced openings therethrough. The openings in the ring are formed so as to allow water to pass therethrough during operation so as to improve the performance characteristics, specifically acceleration, plaining, speed and steering, of the motor. The ring is attached to the motor by an attachment bracket which is designed to inhibit fatigue and cyclical loading failure caused by vibrations of the ring during use. The ring is formed in a generally tapered recangular cross section in order to minimize the drag and vibration characteristics thereof during use. The ring is formed so as to be attachable to an outboard motor to surround the propeller thereof to protect the propeller from underwater objects.

Abstract: A propulsion system for high-speed powerboats whereby the water level in a tunnel containing a surface-piercing propeller is controlled by admitting external air into the tunnel through an air outlet in the tunnel forward of the propeller. The air is admitted through a duct which has an air intake on the exterior of the boat. The duct may contain a valve which may be opened or closed to control the air supply. Particular configurations of the tunnel and the air supply system are disclosed which maximize the ability to control the water level in the tunnel and the degree to which the propeller is submerged as well as best utilize the configuration of the vessel.

Abstract: A motorized propulsion device for swimmers and scuba divers which is to be attached to the user's forearms. The battery, motor, propeller and propeller shroud are arranged in a compact, linear, hydrodynamic manner. The watertight housing may have one or more integrally shaped nesting protuberances to comfortably accommodate the user's forearm and thereby prevent slippage. The front end surface of the housing has a control panel within reach of the user's fingers.

Abstract: A propeller thruster installation includes a propeller unit rigidly supported in an inner tunnel tube which in its turn is elastically coaxially supported in an outer tunnel tube which is rigidly secured to the hull of a ship. In order to reduce the transmission of noise and vibrations from the propeller unit to the interior of, an ship the annulus between the outer and inner tunnel tubes is filled with elastic gas cushions, or a continuously maintained "bubble curtain" of air.

Abstract: A full or partial tunnel wedge is positioned in the propeller shaft tunnel ft of the propeller on a waterborne craft. The size and angle of the wedge is determined by the characteristics of the particular craft. The wedge converges water flow and increases water pressure aft of the propeller. The higher water pressure increases the propeller thrust and reduces the hull drag of the propeller shaft tunnel thus reducing the shaft horsepower required to maintain a given speed.

Abstract: A propulsion drive system for a boat is provided where a propeller is centered within a tunnel. A converging channel, open towards the bottom, extends in front of the tunnel and a converging nozzle extends from the rear of the tunnel. The system is provided with apparatus for mounting the propeller in the center of the tunnel widthwise and a suitable rudder is mounted to the rear of the converging nozzle. The propulsion drive system can operate quietly with little vibration and no cavitation.