A jet propulsion watercraft includes a watercraft body, a drive source in the watercraft body, a jet pump to suck and eject water with a drive force from the drive source to generate a propulsive force, a vibration sensor, and a controller. The vibration sensor is located in the jet pump to detect vibration of the jet pump. The controller is configured or programmed to determine whether or not a detection result from the vibration sensor meets a predetermined condition. The controller is configured or programmed to, when it is determined that the detection result from the vibration sensor meets the predetermined condition, inform a user of user-oriented information.

Thrust with the minimum ejection of propellant by a levitating mass blocking the exhaust stream within the propellant producing structure. The reaction of accumulated propellant pressure between the levitating mass the hollow passageway and the propellant producing engine create thrust thus propelling the propellant producing engine and the vehicle in which it is mounted. Fuel consumption is decrease because a significant amount of propellant is not allowed to escape and is trapped in the vehicle's structure. The levitating mass is not physically attached to the propellant producing engine or the vehicle's structure. The rated pounds of thrust can be significantly increase and is determine by the strength of the magnetic field holding the levitating mass in place the composition of the hollow passageway the mechanical and structural components of the propellant producing engine.

Propulsion device comprising a rotor (14), a stator (15), an outer casing (6), a first base (10) with a central inlet opening (1) configured for fluid intake, and an outlet opening (2) configured for expulsion of propulsive fluid in the form of an outlet jet. The outlet opening (2) is located along the entire perimeter of the propulsion device, wherein the propulsion device comprises: a central valve (3) configured, by means of tilting means, to tilt with a given direction and tilt angle, thereby regulating a flow rate of a fluid inlet jet and a direction of the fluid inlet jet towards a given sector of the propulsion device, and; a perimeter valve (7) configured, by means of tilting means, to tilt with a given direction and angle of tilt, thus regulating a flow rate of the fluid outlet jet and a direction of the fluid outlet jet towards a given sector of the perimeter outlet opening (2).

A jet propulsion watercraft includes a watercraft body, a drive source in the watercraft body, a jet pump to suck and eject water with a drive force from the drive source to generate a propulsive force, a vibration sensor, and a controller. The vibration sensor is located in the jet pump to detect vibration of the jet pump. The controller is configured or programmed to determine whether or not a detection result from the vibration sensor meets a predetermined condition. The controller is configured or programmed to, when it is determined that the detection result from the vibration sensor meets the predetermined condition, inform a user of user-oriented information.