A linear drive system adapted for repetitive driving using a linear motor. The drive system may be used to power pumping hydrofoils which drive a boat or ship. Linkages are used to maintain the driven portion in linear motion. A coupled dual drive system in which two driven portions are coupled such that their coupled motions travel at the same velocity in opposed directions. The coupled linear drive system which may be used as a mechanical power source for drive systems used in transportation and industry. A boat with dual pumping hydrofoils adapted for propel a boat using the hydrofoils for both lift and propulsion.

Provided is a mobile water quality monitoring platform for a fishpond, belonging to the technical field of water quality monitoring devices. The mobile water quality monitoring platform for a fishpond includes a floating body, a first rotating shaft and a second rotating shaft are disposed on the floating body, the first rotating shaft is rotatably disposed on the floating body through two first support plates, two second support plates are vertically disposed on the floating body, an elongated chute hole is horizontally disposed on two second support plates respectively, both ends of the second rotating shaft are inserted into two chute holes respectively, the first rotating shaft and the second rotating shaft are connected through a connecting rod mechanism, a driving mechanism that enables the first rotating shaft and the second rotating shaft to rotate simultaneously is disposed on the connecting rod mechanism.

A linear drive system adapted for repetitive driving using a linear motor. Linkages are used to maintain the driven portion in linear motion. A coupled dual drive system in which two driven portions are coupled such that their coupled motions travel at the same velocity in opposed directions. A linear drive system with a return spring portion which is adapted to facilitate linear direction changeover. A coupled linear drive system which may be used as a mechanical power source for drive systems used in transportation and industry.

A linear drive system adapted for repetitive driving using a linear motor. The drive system may be used to power pumping hydrofoils which drive a boat or ship. Linkages are used to maintain the driven portion in linear motion. A coupled dual drive system in which two driven portions are coupled such that their coupled motions travel at the same velocity in opposed directions. The coupled linear drive system which may be used as a mechanical power source for drive systems used in transportation and industry. A boat with dual pumping hydrofoils adapted for propel a boat using the hydrofoils for both lift and propulsion.

A watercraft system including one or more air passageways and/or one or more water passageways is provided. The air passageways may extend from an upper surface of the watercraft, through the body of the watercraft, to an underneath surface of the watercraft. The water passageways may extend from an underneath forward or side portion on the watercraft, through the body of the watercraft, to a rear portion of the watercraft. The air and/or water passageways may be constricting from the inlets to the outlets so that the air and/or water is accelerated through the passageways during use of the craft. In this way, the release of the accelerated air and/or water decreases the craft's drag and provides the craft a forward thrust.

A watercraft system including one or more air passageways and/or one or more water passageways is provided. The air passageways may extend from an upper surface of the watercraft, through the body of the watercraft, to an underneath surface of the watercraft. The water passageways may extend from an underneath forward or side portion on the watercraft, through the body of the watercraft, to a rear portion of the watercraft. The air and/or water passageways may be constricting from the inlets to the outlets so that the air and/or water is accelerated through the passageways during use of the craft. In this way, the release of the accelerated air and/or water decreases the craft's drag and provides the craft a forward thrust.

Provided is a mobile water quality monitoring platform for a fishpond, belonging to the technical field of water quality monitoring devices. The mobile water quality monitoring platform for a fishpond includes a floating body, a first rotating shaft and a second rotating shaft are disposed on the floating body, the first rotating shaft is rotatably disposed on the floating body through two first support plates, two second support plates are vertically disposed on the floating body, an elongated chute hole is horizontally disposed on two second support plates respectively, both ends of the second rotating shaft are inserted into two chute holes respectively, the first rotating shaft and the second rotating shaft are connected through a connecting rod mechanism, a driving mechanism that enables the first rotating shaft and the second rotating shaft to rotate simultaneously is disposed on the connecting rod mechanism

A mono-fin for swim training is disclosed. The mono-fin has two separated boot structures that from two separate foot cavities for holding feet with toes positioned in front regions of each of the boot structures and heels positioned at back regions of each of the boot structures. The mono-fin has a mono-fin structure with blades portions connecting the boot structure through the front regions of each of the boot structures. In a middle region of the mono-fin structure and between the blade portions, there is flex region. The flex region allows angles between the boot structures, distances between the back regions of the boot structures and angles between the blade portions to be changed simultaneously by a swimmer while swim training in an aquatic environment.

In an oscillating fin propulsion apparatus adapted for use by a disabled diver, a propulsion force may be produced by a fin adapted to sweep back and forth in a generally transverse direction relative to the traveling direction of the diver. The fin may be mounted on a scuba tank operatively connected to drive members that may be reciprocated by the diver. The oscillating fin may provide a propulsive force propelling the diver forward during both oscillating directions of the fin.

A water propulsion apparatus operatively connected to a body moving on or through a body of water, may produce a propulsive force by sweeping fins in an oscillating motion in a generally transverse direction relative to a longitudinal axis of the body. The fins may be mounted on opposite sides of a frame and are rotatable about a first axis coplanar to the center longitudinal axis of the frame. Drive members rotatable about a second axis that is canted relative to the first axis may be operatively connected to the fins. The oscillatory motion of the fins may be controlled by torque applied at the canted second axis by reciprocating the drive members in a generally vertical plane parallel to the center longitudinal axis of the frame. The oscillating fins may provide a propulsive force during both oscillating directions of the fins as they sweep back and forth.