Ship maneuver supporting device and ship maneuver supporting method

A ship maneuver supporting method performed by a device, the ship maneuver supporting method comprising;

• acquiring second ship information on a position and a velocity of a second ship,
• based on the second ship information and on an assumption that the second ship will travel at a constant course and speed, estimating positions of the second ship at a plurality of future time points,
• acquiring first ship information on a position and a velocity of a first ship,
• based on the first ship information and based on the first ship traveling on a course arbitrarily defined from the position of the first ship at a constant first ship traveling speed, estimating positions of the first ship at the plurality of future time points,
• determining a collision risk value for determining whether or not to display a collision risk zone, the collision risk zone being a zone where a collision between the first ship and the second ship may occur in the future,
• wherein the collision risk value is determined at each of the plurality of future time points based on a separating distance between the estimated positions between the first ship and the second ship at each of the plurality of future time points,
• generating collision risk zone display data for displaying the collision risk zone, based on determining that the collision risk value at the one of the plurality of future time points is above a predetermined collision risk threshold, and
• based on the collision risk zone display data, displaying the collision risk zone along the arbitrary course of the first ship on a display,
• wherein the ship maneuver supporting method further comprises:
• setting a watch area relative to a direction of the first ship,
• based on a size of the watch area and the separating distance between the estimated positions between the first ship and the second ship at each of the plurality of future time points, determining a watch risk value for determining whether or not to display a watch zone relative to the collision risk zone,
• upon determining that the watch risk value is above a predetermined watch risk threshold at one of the plurality of future time points, generating watch zone display data for displaying the watch zone adjacent and prior to the collision risk zone along the arbitrary course of the first ship, and
• based on the watch zone display data, displaying the watch zone adjacent and prior to the collision risk zone along the arbitrary course of the first ship in a manner that is distinguishable from the collision risk zone.