A stand-alone modular removable rudder system for watercraft having a rudder comprising a steering handle coupled to a quick release mechanism adapted to releasably secure said steering handle to said watercraft in proximity to the operator, said system further comprising, a rudder mount adapted to be coupled to the rear of the watercraft by a quick release mechanism adapted to releasably secure said rudder mount to said watercraft, said rudder being carried by a rudder support pivotal about said rudder mount and cables operatively connecting said steering handle to said rudder mount whereby the steering handle can be operated to steer the rudder.

A stand-alone modular removable rudder system for watercraft having a rudder comprising a steering handle coupled to a quick release mechanism adapted to releasably secure said steering handle to said watercraft in proximity to the operator, said system further comprising, a rudder mount adapted to be coupled to the rear of the watercraft by a quick release mechanism adapted to releasably secure said rudder mount to said watercraft, said rudder being carried by a rudder support pivotal about said rudder mount and cables operatively connecting said steering handle to said rudder mount whereby the steering handle can be operated to steer the rudder.

The invention provides a structure of a propeller ship which can achieve improvement of fuel consumption, and enlarge an amount of cargo per ship total length. Rudders 12 are provided at laterally symmetrical positions of a ship center line in a front side of a propeller 11 and in a rear side of a buttock line.

The invention provides a structure of a propeller ship which can achieve improvement of fuel consumption, and enlarge an amount of cargo per ship total length. Rudders 12 are provided at laterally symmetrical positions of a ship center line in a front side of a propeller 11 and in a rear side of a buttock line.

Embodiments of the present apparatus and method feature a permanently fixed canted keel. The apparatus and method feature tacking maneuvers which shift the sail element and reverse the direction of the hull form.

Embodiments of the present apparatus and method feature a permanently fixed canted keel. The apparatus and method feature tacking maneuvers which shift the sail element and reverse the direction of the hull form.

To easily grasp a relationship of parameter values which influence a log velocity of a ship, with the log velocity of the ship caused by the parameters, a ship characteristic estimating device is provided, which includes a data outputter configured to output a plurality of parameter data respectively including rotational speed data of a propeller of a ship, and wind velocity vector data of wind force that may act on the ship, and an estimator configured to receive the plurality of parameter data outputted from the data outputter, estimate values corresponding to the respective parameter data to be log velocity vectors of the ship, and output them as first output values. The rotational speed data are same as each other and the wind velocity vector data are different from each other.

The automatic steering device comprises a target rudder angle calculating unit, a target rudder angle storage unit, and a steering command unit. The target rudder angle calculating unit calculates a target rudder angle of a steering based on a heading and a target course. The target rudder angle storage unit stores a target rudder angle at a time of a previous steering command. The steering command unit outputs a steering command for instructing the steering to steer based on a newest target rudder angle calculated by the target rudder angle calculating unit and the target rudder angle at the time of the previous steering command stored by the target rudder angle storage unit.

The automatic steering device comprises a target rudder angle calculating unit, a target rudder angle storage unit, and a steering command unit. The target rudder angle calculating unit calculates a target rudder angle of a steering based on a heading and a target course. The target rudder angle storage unit stores a target rudder angle at a time of a previous steering command. The steering command unit outputs a steering command for instructing the steering to steer based on a newest target rudder angle calculated by the target rudder angle calculating unit and the target rudder angle at the time of the previous steering command stored by the target rudder angle storage unit.

A mast system for use with a sailing vessel including a flexible mast connected to a first point of the sailing vessel; a tether connected to a second point of the sailing vessel, the tether being further connected to the flexible mast, wherein the lengths of the tether and the flexible mast are sized to pull the flexible mast into an arch.