NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Spherical earth model vs. ellipsoid
From: Dan Hogan
Date: 1999 Mar 12, 11:47 AM
From: Dan Hogan
Date: 1999 Mar 12, 11:47 AM
The errors one will get from using celestial navigation at sea. will be not from any mathematical equations. But from a navigator that is "green-around-the gills" after 3-4 days of storm on a small boat bouncing on a rolling ocean. Toss in a hazy sky and uncertain DR and you have it. As the textbooks say. The mid-shipman makes a precise mark on the chart and says, "We are here.". the Fistmate draws a small circle and says, "About here.". The Captain comes in, slaps a spread out hand down and says. "We are someplace around here." On a small boat, making 5-8 knots, a daily Noon sight becomes just about right. Also, living on a boat for days on end that is doing much over 5.5 Knots gets to be downright miserable. So good seamanship dictates that a good lookout, a consistent DR and periodic position fixes be mixed with common sense. So if you get a cocked hat of about six miles, you are someplace around there. Dan Hogan WA6PBY dhhogan@concentric.net Catalina 27 "GACHA" =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=--=-= =-= TO UNSUBSCRIBE, send this message to majordomo@roninhouse.com: =-= =-= unsubscribe navigation =-= =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=--=-=
