NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Leg 56 Question # 3
From: Robert Owens
Date: 1999 Jul 20, 7:02 AM
From: Robert Owens
Date: 1999 Jul 20, 7:02 AM
-----Original Message----- From Lu AbelTo: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM Date: Monday, July 19, 1999 10:46 PM Subject: Re: Leg 56 Question # 3 Snip----- >Way behind - The USPS courses, for example, discuss obtaining speed vs RPM >curves for one's boat. Good 1920's practice when electronic knotmeters >didn't exist. Maybe actually carried into the 1950s by the Navy. Has >anyone on the list actually made such a curve? > Snip I did a Speed vs RPM run after I bought my boat.(26' Nordic Tug) It took me practically all day but I now know how fast my boat moves through the water. Then I calibrated my knotmeters. Both were off quite a bit to my standards and both have adjustments and come with instructions on how to do it. I have both Loran and GPS and do not trust either as true speed indicators. Although the loran is much more accurate than the GPS. I have seen errors up to 1.8 knots on the GPS. Try doing a predicted log event with nothing but a tach and compass. Using your arguments about the 1920's why bother compensating and adjusting your compass. I don't see the difference between a boat and an airplane as far as how fast does it cruise at certain RPM's and how much fuel do I burn. I go at this at a ridiculous extreme. Two decimal points. But I win my local predicted log events and can tell you how much fuel it will take to fill the tanks to the quarter gallon. If I run out of fuel it will be a leak. This dribble is just my opinion. Bob Owens TUGLY 26' Nordic Tug