COURSE and CURRENT     - V.29
calculate the course when a current exists

     (COURSES: Degrees,    SPEED: knots)
Course through Water Speed
Direction of Current    Speed
Course over Ground   


COURSE and CURRENT, Explanation

This program calculates the triangle of a ships course-through-water (CTW) under some current (DUC) giving finally a course-over-ground (COG). Enter first the ships true course and speed through the water, and then eventually the current and its speed and/or the desired course-over-ground. If course-over-ground is not defined, this will be calculated by the program. On the other hand, if course-over-ground is specified, the program will re-calulate course-through-water with the given value of speed. In that latter case, the input for course-through-water is ignored. -
(As the vector-relation CTW + DUC = COG holds, you may use this program to eventually calculate the current DUC from the course-data: -CTW + COG = DUC. The minus-sign is handled by adding 180° to CTW before entering, but keeping the corresponding speed.) The ship is assumed to move forward only.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the license or any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License ( for more details.
If errors are encountered, kindly send a note to Author: Heiner Müller-Krumbhaar   - Last update 18.may.2023.