A floating vessel comprising: (a) opposing hulls; (b) a beam extending between and interconnecting the opposing hulls; and (c) a deck supported by the beam and positioned between the opposing hulls, wherein the floating vessel is modular and configured for easy assembly, disassembly, or both.

An electric marine propulsion system is configured to propel a marine vessel and comprises a lithium ion (LI) battery, a marine drive having an electric motor powered by the LI battery, and a user input device configured to receive a user input selected an emergency depletion mode. The system further includes a controller configured to determine a battery charge level for the LI battery and reserve a minimum charge level of the LI battery associated with a normal operating area for the LI battery by ceasing power delivery from the LI battery to the marine drive once the battery charge level reaches the minimum charge level. In response to selection of the emergency depletion mode, power is delivered from the LI battery to the marine drive when the battery charge level is below the minimum charge level.

An electric marine propulsion system is configured to propel a marine vessel and comprises a lithium ion (LI) battery, a marine drive having an electric motor powered by the LI battery, and a user input device configured to receive a user input selected an emergency depletion mode. The system further includes a controller configured to determine a battery charge level for the LI battery and reserve a minimum charge level of the LI battery associated with a normal operating area for the LI battery by ceasing power delivery from the LI battery to the marine drive once the battery charge level reaches the minimum charge level. In response to selection of the emergency depletion mode, power is delivered from the LI battery to the marine drive when the battery charge level is below the minimum charge level.

A method of controlling an electric marine propulsion system configured to propel a marine vessel and powered by a power storage system includes presenting on a user interface a plurality of power mode options selectable by a user, including at least a reduced power and an emergency power mode. Upon selection of the reduced power mode by the user, at least one auxiliary devices utilizing power from the power storage system is automatically turned off and the propulsion system is controlled so as not to exceed a first speed limit. Upon selection of the emergency power mode by the user, the at least one auxiliary device utilizing power from the power storage system is turned off and the propulsion system is controlled so as not to exceed a second speed limit that is lower than the first speed limit.

A method of controlling an electric marine propulsion system configured to propel a marine vessel and powered by a power storage system includes presenting on a user interface a plurality of power mode options selectable by a user, including at least a reduced power and an emergency power mode. Upon selection of the reduced power mode by the user, at least one auxiliary devices utilizing power from the power storage system is automatically turned off and the propulsion system is controlled so as not to exceed a first speed limit. Upon selection of the emergency power mode by the user, the at least one auxiliary device utilizing power from the power storage system is turned off and the propulsion system is controlled so as not to exceed a second speed limit that is lower than the first speed limit.

There are described herein methods and systems for operating an electric motor of a watercraft. In one method, the electric motor of the watercraft is controlled based on commands received from an accelerator of the watercraft, a sensor signal is received from at least one sensor of the watercraft while the electric motor is in operation, the sensor signal indicative of an undesirable condition of a water intake of the watercraft, and a change is effected to the controlling of the electric motor in response to receiving the sensor signal.

There are described herein methods and systems for operating an electric motor of a watercraft. In one method, the electric motor of the watercraft is controlled based on commands received from an accelerator of the watercraft, a sensor signal is received from at least one sensor of the watercraft while the electric motor is in operation, the sensor signal indicative of an undesirable condition of a water intake of the watercraft, and a change is effected to the controlling of the electric motor in response to receiving the sensor signal.

There are described herein methods and systems for operating an electric motor of a watercraft. In one method, the electric motor of the watercraft is controlled based on commands received from an accelerator of the watercraft, a sensor signal is received from at least one sensor of the watercraft while the electric motor is in operation, the sensor signal indicative of an undesirable condition of a water intake of the watercraft, and a change is effected to the controlling of the electric motor in response to receiving the sensor signal.

A handheld underwater aircraft includes a battery compartment (12) and propellers. There are at least two propellers, which are symmetrically distributed on both sides of the battery compartment (12), and are connected to the battery compartment (12). A special design with axes of the propellers being unparallel with an axis of the battery compartment (12) is adopted, and unparallel included angles make component forces generated by the various propellers in a direction of motion of a non-underwater aircraft offset each other, and enable the underwater aircraft to maintain balanced and forward-forward motion. The design with the axes of the propellers being unparallel with the axis of the battery compartment (12) leads to a little power loss, but avoids a larger power loss caused by the impact of water on the human body, thereby comprehensively improving the thrust of the underwater aircraft in use.

An unmanned vehicle capable of tunneling into soft materials, such as sand, comprises a hollow, bullet-shaped forward outer body with a first drive screw thread integrated into its exterior, a hollow cylindrical rear outer body with a second drive screw thread integrated into its exterior but threaded in the opposed direction of the first drive screw thread, and an inner body that is rotatably coupled to the inside of the forward and rear outer bodies via mechanical gears, and including directional control fins mounted on a housing at the rear end of the inner body.