NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Taffrail log and an alternative
From: Walter Guinon
Date: 2002 Jun 23, 05:23 -0700
From: Walter Guinon
Date: 2002 Jun 23, 05:23 -0700
If the clockwork presents low drag the slip of the fish is very low and the fish moves thru the water like a screw in wood. Thus I suggest the accuracy of a tafrail log is better than one percent. Unfortunately it doesn't perform so well in southern waters since it continually fouls with Sargasso weed. Don't forget to keep the fish painted black since it looks like a tasty treat to many of the denizens and at $40 per replacement can seriusly reduce your beer ration. There is a braided closline for sale that works as well as the "special" and costly log line sold for the purpose. Many paddle wheel logs are defficient at low speeds. The magnetic sensor gives an impulse whether rotated forward or backwards. Thus whenever the water flow is from aft to forward the distance traveled is incremented instead of decremented. To approach the same accuracy as a taffrail log one must calibrate for different sea conditions and headings. The chip log seems like a good idea if it is streamed regularly but I never figured out how to reteive it easily at speed due to its drag. Walter Guinon Lincolnville Maine __________________________________________________ Do You Yahoo!? Yahoo! - Official partner of 2002 FIFA World Cup http://fifaworldcup.yahoo.com