Finding Declination

Several websites can be used to find the declination at a particular location. magnetic-declination.com allows you to click on a zoomable world map and view the declination of that location.

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Compass

The ROV compass system is designed to display headings relative to Magnetic North. You can enter a local compass variation to account for magnetic declination. The declination is considered positive when the Magnetic North is East of True North.

The value you enter is numerically added to the heading from the ROV. For example, if you are in an area with a declination of 15 degrees West, the ROV heading will read +15 degrees when the ROV is facing True North (assuming no variation has been entered). You should therefore enter -15 for the variation, which would result in a correct True North reading of 0 when the ROV is pointed True North.

The declination is saved from session to session. Be sure to clear it or change it at the start of each session if necessary.

Beginning with version 1.8 of VideoRay Cockpit, the behavior of the Compass Variation has been reversed. In prior versions, the variation was subtracted from the ROV heading.

You can use the Turns Indicator instrument to facilitate easier navigation with respect to a fixed reference such as a dock. See the sections on the Turns Indicator instrument and Relative Heading for more information about using the Turns Indicator settings.