A method of controlling an adjustable exhaust system for a marine engine includes receiving a vessel location of a marine vessel having an adjustable exhaust system and identifying a noise constraint based on the vessel location. A current exhaust mode of the adjustable exhaust system is identified. A determination is then made regarding whether the exhaust system is exceeding the noise constraint based on the current exhaust mode. If the noise constraint is exceeded, an instruction is generated to adjust the adjustable exhaust system to comply with the noise constraint.

A method of controlling an adjustable exhaust system for a marine engine includes receiving a vessel location of a marine vessel having an adjustable exhaust system and identifying a noise constraint based on the vessel location. A current exhaust mode of the adjustable exhaust system is identified. A determination is then made regarding whether the exhaust system is exceeding the noise constraint based on the current exhaust mode. If the noise constraint is exceeded, an instruction is generated to adjust the adjustable exhaust system to comply with the noise constraint.

A controller performs hydrolock prevention control when an engine is started. The controller determines whether a crankshaft rotates a predetermined number of times upon starting the engine without ignition of the engine. The controller performs the ignition of the engine after the crankshaft rotates a predetermined number of times.

A controller performs hydrolock prevention control when an engine is started. The controller determines whether a crankshaft rotates a predetermined number of times upon starting the engine without ignition of the engine. The controller performs the ignition of the engine after the crankshaft rotates a predetermined number of times.

A computer-implemented method of tracking vessel movement which comprises receiving a first vessel data message comprising a first vessel identifier, the first vessel data message having been transmitted at a first time and being associated with a first position; and receiving a second vessel data message comprising a second vessel identifier, the second vessel data message having been transmitted at a second time and being associated with a second position. The method also comprises determining if the first vessel identifier and the second vessel identifier are related. If the first vessel identifier and the second vessel identifier are related, a speed required for a vessel to have moved from the first position to the second position is determined; which is then determined if the speed is below a speed threshold; and if the speed is below the speed threshold, the first position is associated with the second position.

A computer-implemented method of tracking vessel movement which comprises receiving a first vessel data message comprising a first vessel identifier, the first vessel data message having been transmitted at a first time and being associated with a first position; and receiving a second vessel data message comprising a second vessel identifier, the second vessel data message having been transmitted at a second time and being associated with a second position. The method also comprises determining if the first vessel identifier and the second vessel identifier are related. If the first vessel identifier and the second vessel identifier are related, a speed required for a vessel to have moved from the first position to the second position is determined; which is then determined if the speed is below a speed threshold; and if the speed is below the speed threshold, the first position is associated with the second position.

According to an example aspect of the present invention, there is provided a marine propulsion system (1) comprising a first portion (4) and a second portion (5) of a set of movable foils, a movement mechanism (2) coupled to the first portion (4) and the second portion (5) of the set of movable foils and configured to simultaneously control a motion of the first portion (4) and the second portion (5) of the set of foils along a closed first trajectory (6) comprising a first direction (17) and a second direction (18) which is different than the first direction (17), and a pitch mechanism (3) coupled to the first portion (4) and the second portion (5) of the set of movable foils and configured to control a pitch angle (π) of the first portion (4) and the second portion (5) of the set of movable foils, and wherein the pitch angle (π) of at least a part of the second portion (5) of the set of foils is dependent on an incoming fluid flow (v.sub.x), the motion of the second portion (5) of the set of foils, and a flow (v.sub.ind) induced by at least a part of the first portion (4) of the set of foils.

According to an example aspect of the present invention, there is provided a marine propulsion system (1) comprising a first portion (4) and a second portion (5) of a set of movable foils, a movement mechanism (2) coupled to the first portion (4) and the second portion (5) of the set of movable foils and configured to simultaneously control a motion of the first portion (4) and the second portion (5) of the set of foils along a closed first trajectory (6) comprising a first direction (17) and a second direction (18) which is different than the first direction (17), and a pitch mechanism (3) coupled to the first portion (4) and the second portion (5) of the set of movable foils and configured to control a pitch angle (π) of the first portion (4) and the second portion (5) of the set of movable foils, and wherein the pitch angle (π) of at least a part of the second portion (5) of the set of foils is dependent on an incoming fluid flow (v.sub.x), the motion of the second portion (5) of the set of foils, and a flow (v.sub.ind) induced by at least a part of the first portion (4) of the set of foils.

A system for flushing a cooling water pathway of a marine propulsion device with water supplied from a water source includes a water control device and a controller. The water control device is connected to the water source and the cooling water pathway of the marine propulsion device. The controller controls and causes the water control device to supply the water from the water source to the cooling water pathway so as to perform the flushing. The controller obtains propulsion device data including at least one of a pressure of the water, a flow rate of the water and a concentration of salt contained in the water in the cooling water pathway. The controller determines whether or not to stop a supply of the water by the water control device based on the propulsion device data.

A system for flushing a cooling water pathway of a marine propulsion device with water supplied from a water source includes a water control device and a controller. The water control device is connected to the water source and the cooling water pathway of the marine propulsion device. The controller controls and causes the water control device to supply the water from the water source to the cooling water pathway so as to perform the flushing. The controller obtains propulsion device data including at least one of a pressure of the water, a flow rate of the water and a concentration of salt contained in the water in the cooling water pathway. The controller determines whether or not to stop a supply of the water by the water control device based on the propulsion device data.