Marine navigation device using two pivoting discs and rules to determine position on chart from GPS data

摘要

A device for determining a position on a navigational chart on the basis of GPS data, comprising a rapid orientation and positioning assembly having two discs arranged one on top of the other and used as a protractor and a reader, respectively, said discs being pivotably joined together in the middle by a pointing means and two positioning rules. The upper rule is also used for orientation and both rules have a central longitudinal aperture while the edges of the rules include a projection enabling each rule to slide freely along a respective mortised recess in each disc. The upper rule is provided with a double longitudinal scale. Said device is particularly useful as an aid for work on navigational charts.