A marine vessel control system comprises a propulsion unit and a steering actuator for steering the propulsion unit. There is a shift actuator for shifting gears in the propulsion unit and a throttle actuator for increasing or decreasing throttle to the propulsion unit. There is an input device for providing user inputted steering commands to the steering actuator and for providing user inputted shift and throttle commands to the shift actuator and the throttle actuator. There is a sensor for detecting a global position and a heading direction of the marine vessel. A controller receives position and heading values of the marine vessel from the sensor. The controller compares the received position value to a pre-programmed position value to determine a position error difference. The controller also compares the received heading value to a pre-programmed heading value to determine a heading error difference.

A ship handling device executing dynamic positioning control with which the fixed-point maintaining accuracy including measurement accuracy of a satellite positioning system can be assessed. In this ship handling device (7) for maintaining a ship body (1) at a target position (Y) using a GNSS (Global Navigation Satellite System) device (13), a positioning accuracy level (19) of the GNSS device is calculated based on a radio-wave reception state of the GNSS device, a fixed-point deviation amount level (20) is calculated based on a fixed-point deviation amount calculated based on the target position and a measured position (X) measured by the GNSS device, and a fixed-point maintaining accuracy level (21) indicative of an assumed range of an absolute position (Z) of the ship body relative to the target position is determined with reference to the positioning accuracy level and the fixed-point deviation amount level.

Various embodiments of the invention provide a buoy and system for monitoring divers and other underwater objects. In many embodiments, the buoy has capabilities to monitor a diver, obtain position information about the diver and use that information to move itself to an effective range for continued monitoring. The buoy can connect and communicate with a communication device attached to a diver to communicate, position, biometric and other data. In one embodiment, the buoy comprises a propulsion system for propelling the buoy, an acoustic communication module for communicating with the diver and a propulsion controller for controlling the propulsion system to move to the effective range. Other embodiments provide a power generation system using a power generating buoy comprising an inertial weight, an energy converter and a connecting linkage. The system may comprise a single or multiple buoys and can include an electrical storage such as an electrical battery.

Virtual anchor features for a navigation/autopilot system for use on a marine vessel are provided herein. An example apparatus associated with a marine vessel includes a processor and memory including computer program code, the memory and the computer program code configured to, with the processor, cause the apparatus to receive user input indicating at least a first geographic location and a desired offset distance; determine a current geographic location of at least one of the marine vessel or the apparatus; determine if the current geographic location is within a distance threshold of the desired offset distance from the first geographic location; and cause, in an instance in which the current geographic location is not within the distance threshold, one or more motors of the marine vessel to operate to cause the marine vessel to move to a new geographic location accordingly. A desired orbit pattern may also be employed.

A ship handling device capable of executing dynamic positioning control. While the dynamic positioning control is being active, if a distance deviation from a target position exceeds a predetermined value and a first condition that a state where a moving amount of the ship per unit time is not more than a predetermined amount has continued for a predetermined period is satisfied, or if an orientation deviation from a target orientation exceeds a predetermined value and a second condition that a state where a turning amount of the ship per unit time is not more than a predetermined amount has continued for a predetermined period is satisfied, a thrust setting value resulting from the dynamic positioning control at a determination on the first or second condition is stored as a reference value, and the reference value is added to a thrust setting value subsequently resulting from the dynamic positioning control.

A method for controlling movement of a marine vessel includes controlling a propulsion device to automatically maneuver the vessel along a track including a series of waypoints, and determining whether the next waypoint is a stopover waypoint at or near which the vessel is to electronically anchor. If the next waypoint is the stopover waypoint, a control module calculates a distance between the vessel and the stopover waypoint. In response to the calculated distance being less than or equal to a threshold distance, the propulsion device's thrust is decreased. In response to sensing that the vessel thereafter slows to a first threshold speed, the vessel's speed is further reduced. In response to sensing that the vessel thereafter slows to a second, lower threshold speed or passes the stopover waypoint, the propulsion device is controlled to maintain the vessel at an anchor point that is at or near the stopover waypoint.

A catamaran lifting apparatus is disclosed for lifting objects in a marine environment. The apparatus includes first and second vessels that are spaced apart during use. A first frame spans between the vessels. A second frame spans between the vessels. The frames are spaced apart and connected to the vessels in a configuration that spaces the vessels apart. The first frame connects to the first vessel with a universal joint and to the second vessel with a hinged connection. The second frame connects to the second vessel with a universal joint and to the first vessel with a hinged or pinned connection. Each of the frames provides a space under the frame and in between the barges that enables a package to be lifted and/or a marine vessel to be positioned in between the barges and under the frames. In this fashion, an object that has been salvaged from the seabed can be placed upon the marine vessel that is positioned in between the barges and under the frames.

A control system for controlling a vessel, a method for controlling dynamic positioning of the vessel or ship, and a computer program for carrying out the method are disclosed. The vessel includes an electrical power grid, at least one combustion engine driven power generator, and an energy storage medium. The power grid is arranged to provide power to an electric motor driving one or more thrusters or propellers of the vessel. The control system further includes a control unit arranged with computer programs and hardware configured to: calculate a Remaining Operation Window time for carrying out dynamic positioning powered by the energy storage medium, generate and display information including a time period for the Remaining Operation Window of dynamic positioning, and carry out an automatic control action in relation to at least one of a power generator or power consuming device connected to the power grid.

A multi-anchor depth control system for a boat or other watercraft having a line for securing anchors to the boat, at least two anchors attached at or near opposing ends of the line, a depth finder, and a controller configured to automatically adjust the amount of line released from the boat to maintain the anchors on the floor of the body of water in which the boat is floating, based upon information obtained from the depth finder.

A method for maintaining position and/or heading of a marine vessel in a body of water includes accepting a command to maintain the vessel at an initial selected position and/or heading, and utilizing position/heading feedback control to determine initial steering angles, gear positions, and engine speeds for the vessel's propulsion devices that cause the propulsion devices to produce thrust that counteracts a net external force and moment on the vessel and maintains the vessel at the initial selected position/heading. The method also includes propelling the vessel to a new selected position/heading, and accepting a command to maintain the vessel at the new selected position/heading. The method next includes utilizing information related to one of the position/heading feedback control and the propulsion devices' thrust to predict control parameters required to maintain the vessel at the new selected position/heading, and controlling the propulsion device according to the predicted control parameters.