An engine device including: an intake manifold configured to supply air into a cylinder; an exhaust manifold configured to output exhaust gas from the cylinder; a gas injector which mixes a gaseous fuel with the air supplied from the intake manifold; and a main fuel injection valve configured to inject a liquid fuel into the cylinder for combustion. At the time of switching the operation mode from one to the other between a gas mode and a diesel mode, an instant switching to the diesel mode is executed when the engine rotation number is determined to approach the upper limit value which leads to an emergency stop of the engine device.

An engine device (21) including: an intake manifold (67) configured to supply air into a cylinder (77), an exhaust manifold (44) configured to output exhaust gas from the cylinder; a gas injector (98) which mixes a gaseous fuel with the air supplied from the intake manifold; and a main fuel injection valve (79) configured to inject a liquid fuel into the cylinder for combustion. At the time of switching the operation mode from one to another between a gas mode and a diesel mode, a supply amount of a first fuel to be supplied in a post-switching operation mode is increased to a switching threshold value through an increase control which monotonously increases the supply amount, and then is controlled by a speed-governing control based on the engine rotation number. The switching threshold value is set based on the engine rotation number or the engine load.

An engine device (21) including: an intake manifold (67) configured to supply air into a cylinder (77), an exhaust manifold (44) configured to output exhaust gas from the cylinder; a gas injector (98) which mixes a gaseous fuel with the air supplied from the intake manifold; and a main fuel injection valve (79) configured to inject a liquid fuel into the cylinder for combustion. At the time of switching the operation mode from one to another between a gas mode and a diesel mode, a supply amount of a first fuel to be supplied in a post-switching operation mode is increased to a switching threshold value through an increase control which monotonously increases the supply amount, and then is controlled by a speed-governing control based on the engine rotation number. The switching threshold value is set based on the engine rotation number or the engine load.

Propulsion system for assistance when paddling in surfing; comprising a propellant device (1), hydro jet type, intended to be mounted on a surfboard (T); and a control device (2) in the manner of a bracelet or bracelet suitable for its attachment on a users arm. The control device (2) comprises: a microprocessor (21), a supply battery (22), sensors (23) that provide the microprocessor (21) with suitable data to identify the users rowing action, calculating the speed and intensity of paddling and generating a control signal proportional to the paddling intensity of the user and; a wireless communication means (24) that transmits the control signal to the propelling device (1); and wherein said propelling device (1) varies the propulsion power as a function of the signals received from the control device (2).

A small marine vessel includes a vessel body, a propulsion device, a propulsion device housing provided in a rear portion of the vessel body and that houses the propulsion device, a first cover that substantially covers and seals the propulsion device housing, and a second cover disposed above the first cover and that covers the first cover and an opening of the propulsion device housing.

An engine device (21) including: an intake manifold (67) configured to supply air into a cylinder (77); an exhaust manifold (44) configured to output exhaust gas from the cylinder (77); a gas injector (98) which mixes a gaseous fuel with the air supplied from the intake manifold 67; and a main fuel injection valve (79) configured to inject a liquid fuel into the cylinder (77) for combustion. At the time of switching the operation mode from one to the other between a gas mode and a diesel mode, an instant switching to the diesel mode is executed when the engine rotation number is determined to approach the upper limit value which leads to an emergency stop of the engine device.

A computing apparatus that is integrated within a flotation module, the system obtaining the energy required to power its computing operations from waves that travel across the surface of a body of water on which the flotation module sets. Additionally, the self-powered computing apparatus employs novel designs to utilize its close proximity to the body of water and/or to strong ocean winds to significantly lower the cost and complexity of cooling their computing circuits.

A computing apparatus that is integrated within a flotation module, the system obtaining the energy required to power its computing operations from waves that travel across the surface of a body of water on which the flotation module sets. Additionally, the self-powered computing apparatus employs novel designs to utilize its close proximity to the body of water and/or to strong ocean winds to significantly lower the cost and complexity of cooling their computing circuits.

A power system for an unmanned surface vehicle is disclosed. In one embodiment, the power system includes a fuel cell, a fuel storage, and an air management system. The fuel cell includes a fuel cell stack. The fuel cell stack includes a fuel inlet, an air inlet, and an exhaust outlet. The fuel storage includes at least one fuel-storage module fluidly connected to the fuel inlet of the fuel cell stack. The fuel-storage module is a source of energy for the fuel cell. The air management system is fluidly connected to the air inlet and the exhaust outlet of the fuel cell. An air snorkel is part of the air management system and provides air to operate the fuel cell while the unmanned surface vehicle is deployed on a surface of a body of water. The air snorkel includes an intake and an exhaust.

A power system for an unmanned surface vehicle is disclosed. In one embodiment, the power system includes a fuel cell, a fuel storage, and an air management system. The fuel cell includes a fuel cell stack. The fuel cell stack includes a fuel inlet, an air inlet, and an exhaust outlet. The fuel storage includes at least one fuel-storage module fluidly connected to the fuel inlet of the fuel cell stack. The fuel-storage module is a source of energy for the fuel cell. The air management system is fluidly connected to the air inlet and the exhaust outlet of the fuel cell. An air snorkel is part of the air management system and provides air to operate the fuel cell while the unmanned surface vehicle is deployed on a surface of a body of water. The air snorkel includes an intake and an exhaust.