NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Hewitt Schlereth
Date: 2011 Apr 14, 09:38 -0400
Hewitt
apacherunner wrote: "�finding boat speed by counting the time it takes a piece of flotsam to move along the hull."
I know that as the "spitlog". I think moist snuff was preferred as "instrument".
It is very easy to calculate and use in the metric system.
1kn = 1nm / 1hour = 1852m / 3600s = 0,51 m/s ≈ 0,5 m/s.
Thus for a boat: Speed (kn) = 2*Length (m) / Time (s).
For my boat, 10m, I divide 20 with time in seconds.
It can't be used on short high-speed boats.Paul Werner
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