A boat includes at least three trim devices positioned aft of the boat's transom. To improve the boat's ability to get on place, each trim device is initially positioned to a deployed position. The speed of the boat is then determined as the boat gains speed. When the speed of the boat exceeds a first predetermined threshold, the first trim device is moved from the deployed position to a non-deployed position. When the speed of the boat exceeds a second predetermined threshold, the second trim device is moved from the deployed position to a non-deployed position. When the speed of the boat exceeds a third predetermined threshold, the third trim device is moved from the deployed position to a non-deployed position. At least one of the first, second, and third predetermined thresholds is different from the other two of the first, second, and third predetermined thresholds.

A system for monitoring a physical change of a marine structure includes a complex optical measuring instrument configured to detect a behavior and structural change of the marine structure by using at least one optical sensor by means of optical fiber Bragg grating.

A sailing vessel is disclosed which comprises a hull, a keel depending from the hull and a mast. A ballast bulb is provided at the lower end of the keel. A first control mechanisms is provided for rotating the ballast bulb about a transverse axis to change the angle of attack of the bulb. A second control mechanism is provided for rotating the bulb about a longitudinal axis of the vessel.

A system for monitoring a physical change of a marine structure includes a complex optical measuring instrument configured to detect a behavior and structural change of the marine structure by using at least one optical sensor by means of optical fiber Bragg grating.

Provided is a transverse metacenter height estimation device that includes: a history storage means for storing time sequence data of the roll angle of a hull; and a transverse metacenter height estimation means that estimates the transverse metacenter height of the hull on the basis of the time sequence data of the roll angle of the hull, such data stored by the history storing means. The transverse metacenter height estimation device is characterized in that the transverse metacenter height estimation means first calculates a roll natural frequency on the basis of the time sequence data of the roll angle of the hull, sets the calculated roll natural frequency as an observation model, carries out state estimation on the basis of a normal state spatial model in which the transverse metacenter height and the gyration radius of the hull are used as state variables, and thereby estimates the transverse metacenter height.

A system for monitoring a physical change of a marine structure includes a complex optical measuring instrument configured to detect a behavior and structural change of the marine structure by using at least one optical sensor by means of optical fiber Bragg grating.