A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2016 Feb 19, 14:34 -0800
Gary said: You can use theE6B on your boat for time speed distance and correction for current just divide by 10.
And if you’ve got a scrap outer you no longer need, you can use typists whiteout to obliterate 360, 030, 060 etc and write in the hours 12, 1, 2 etc (or 12, 11, 10). Then, if you use the squared bit of the slide marked with the tidal range, and assuming a sinusoidal tidal height pattern, you can use it like ‘tide poles’ to work out the height of the tide at any time in the next few hours. Swing the face until the time of high water is at the top against zero drift; place the ‘mean level’ under the dot; and mark half the ‘range’ on the face in pencil above the dot. Swing the face to the required time to get the height of tide. However, this does rather muck up the front of the Douglas for anything else, so only modify a scrap one in case you decide to take up flying again. The white stuff takes a lot of rubbing off. DaveP