An arrangement and a method for installing a propulsion unit to a hull of a ship. The propulsion unit comprises an upper part of the propulsion unit attachable to the hull of the ship and a lower part of the propulsion unit where to a propeller shaft is rotatably supported, and the upper part of the propulsion unit having flanges to attach the flanges tightly to the hull, and wherein there is an aperture in the bottom of the hull where to the propulsion unit is to be installed. The arrangement comprises a plurality of watertight covers covering openings in the bottom of the hull and a plurality of watertight covers covering openings in the top of the upper part of the propulsion unit, wherein the arrangement comprises a removable hull-side cover covering at least the opening under it, and at least one removable propulsion unit side cover covering the opening under it and facing the opening, and the removable covers are bolted from the hull-side.

An exemplary method is disclosed for estimating operational efficiency of a marine vessel with a propeller mounted to a rotatable shaft for converting rotative shaft power transferred from the shaft to the propeller into thrust to propel the marine vessel across water, the method including obtaining a respective time series of values for operating parameters of the marine vessel; constructing a multi-dimensional power matrix for a first time period based on operating parameter values within a respective sub-series thereof that represents a first time period; computing, for one or more propulsion parameters, fouling values based on information stored in the power matrix and information stored in a base matrix, of a reference fouling level; and creating indications concerning operating status of the marine vessel in dependence of the fouling values.

The present disclosure is directed toward a marine exhaust system in which the marine exhaust is directed into the water via an exhaust system integrated within a marine rudder. Exhaust travels from the engine to the rudder via a pipe or tube and is expelled through a cavity in the rudder outward into the water. A swivel is located in the system to allow the rudder to rotate in normal steering operations to allow at least a portion of the exhaust pipe or tube to remain static.

There is described a hinge for detachably connecting a door or window to a wall or a frame such as a windshield. The hinge comprising a shaft extending longitudinally, further comprising a blocker which is extendable about the shaft. A first socketed member is fixed to the shaft, and a second socketed member comprises a lumen for sliding the shaft therein. The lumen comprises a cavity larger than a remainder of the lumen and which defines an inward edge on which the blocker abuts, thereby retaining the shaft in the lumen. The shaft comprises an inner recess which can house the blocker therein if the inner recess is aligned with the blocker, thereby retracting the blocker from the cavity and releasing the shaft from the second socketed member and allowing the first socketed member and the second socketed member to be separated. This can be useful for detaching a door of a boat windshield, for example.

A submarine survey platform, including: a gasbag; a gas tube; a floater; an upper longitudinal plate; a lower longitudinal plate; diaphragm plates including upper openings, lower openings, and trapezoid openings disposed between the upper openings and the lower openings; and diagonal braces. The upper longitudinal plate includes a flat plate and a flanged plate. The lower longitudinal plate is a rectangular plate. The upper longitudinal plate pass through the upper openings, and the lower longitudinal plate pass through the lower openings. The diagonal braces and longitudinal stiffeners are disposed between every two adjacent diaphragm plates. Two diaphragm plates at two ends of the flat plate are provided with a lifting lug. The diagonal braces are symmetrically disposed and include outward braces and inward braces which are crossed with each other. Cross points of the upper/lower longitudinal plate with the diaphragm plates are support points of the upper/lower longitudinal plate.

A monitor device includes a memory, a hardware mount configured to attach to a rigging member, a motion sensor configured to detect a first motion characteristic of the rigging member, and a processor operatively coupled to the memory and to the motion sensor. The processor is configured to receive the first motion characteristic from the motion sensor. The processor is further configured to send the first motion characteristic to a controller. The controller is configured to receive a second motion characteristic generate an output for a display based on the first motion characteristic and the second motion characteristic.

The disclosure relates to a method of applying a coating to an external surface of a man-made object to be at least partly immersed in water (e.g. a vessel or an offshore drilling station) for a time period wherein there is relative movement between the immersed object and the water. The applied coating has a minimal resistance rating for a set of coatings. The method comprises a computer-implemented coating selection process, which comprises a first steps of obtaining, for each coating in the set of coatings, a total roughness value of the external surface based on a fouling roughness value, a macro roughness value and a micro roughness value associated with each coating. The coating selection process comprises in a second step selecting a coating from the set of coatings, wherein the selected coating has a minimal resistance rating associated with the obtained total roughness value for the time period. The method further comprises applying the selected coating to the external surface of the man-made object.

An exemplary method for a marine vessel having a propeller mounted to a rotatable shaft for converting rotative shaft power transferred from the shaft to the propeller into thrust to propel the marine vessel across water, includes obtaining measurement values that are descriptive of the shaft power, the thrust and speed through water of the marine vessel; separately estimating at least one of first excess shaft power caused by fouling of the propeller and second excess shaft power caused by fouling of the hull of the marine vessel; and issuing an indication of propeller cleaning in dependence of the first excess shaft power and hull cleaning in dependence of the second excess shaft power.

The present disclosure relates to pontoon shields. The pontoon shields disclosed herein may, for example, protect pontoons from damage and/or enhance the aesthetic appearance of pontoons. The shields may be fashioned from one or more segments of resilient material configured to attach along a longitudinal aspect of a pontoon. The shields may be fashioned from a single segment, or from one or more segments configured to mate with one another. The shields may be attached to a pontoon, for example, via an adhesive, weld, and/or one or more brackets, or other mechanical means.

A system (102) is configured to monitor energy usage of a surface maritime vessel (100). The system comprises a device (102A) configured to receive characteristic data representing at least one operating characteristic of the vessel, and a device (102A) configured to receive model data representing at least one energy usage model for the vessel. The system further includes a device (102A) configured to process the characteristic data and the model data to generate an output representing a comparison between the characteristic data and the model data.