NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: from a watcher
From: Dave Weilacher
Date: 2002 Oct 17, 18:10 -0700
From: Dave Weilacher
Date: 2002 Oct 17, 18:10 -0700
I teach this stuff in my spare time and know that some of what I advocate will be frowned on by our learned collegues here. But here is a different view. You need a universal plotting sheet. Set this up before you leave. Keep it below. Keep your DR on this one. You need to set up some extras to work sights on. Keep these below also. Only take two books with you, The nautical almanac and the one volume of the sight reduction tables you require. Take lined tablet paper. Throw out the proformas. Stick with just the sun for awhile. Before you go again, practice writing the following on your paper. You need to memorize this. (and what it means) DR-Lat DR-lon W-time W-error ZT ZD GMT G-date HS Ic Dip Ha Mc Ho GHA-h GHA-ms sum SHA/v GHA AP-lon LHA Decl d__ d-corr Decl AP-lat Decl LHA Hc d Z Zn Lop Hc d-corr Hc Ho Hc T/A AP-Lat AP-Lon T/A Lop (Did this from memory BTW.) Short cuts: Look at little d at bottom of column. Usually not big enough to mess with. Keep an accurate watch on GMT and you can skip all of the watch stuff. Use a standard height of eye for your boat and don't worry about the error a couple feet either way will cause. Skip the little d's if they look like they are little corrections. Never mess with the z correction because a 1 degree error here won't make an error of 1 mile at 60 nm from intercept. Only take multiple sights if you aren't happy with the one you took. After you reduce it, if you are off more than 10% of your distance travelled since last fix, you should take another. Or take multiples, then reduce the one(s) that felt best. Also. Only use pencil and paper. Four function calculators don't gain you that much and you really do get better through practice. When ashore, do pencil arithmetic on other things. If you learn your skills ashore, when you get to sea, you'll have easy days. Besides, people think you are a weird sort of cool when they see you working a pencil. On Wed, 16 Oct 2002 13:06:22 +0100 martinhallwrote: > Clean > Clean > DocumentEmail > > MicrosoftInternetExplorer4 > > > > st1\:*{behavior:url(#default#ieooui) } > > > > > > > > /* Style Definitions */ > table.MsoNormalTable > {mso-style-name:"Table Normal"; > mso-tstyle-rowband-size:0; > mso-tstyle-colband-size:0; > mso-style-noshow:yes; > mso-style-parent:""; > mso-padding-alt:0cm 5.4pt 0cm 5.4pt; > mso-para-margin:0cm; > mso-para-margin-bottom:.0001pt; > mso-pagination:widow-orphan; > font-size:10.0pt; > font-family:"Times New Roman";} > > > > > > > > > Hi > > I have watched this list for some time now > avidly reading and trying to absorb all the > information passed on it. > > Last year I took the RYA offshore nav > course but have problems implementing the > content. > > I only have a very small boat and do most > of my sailing in the Bristol > channel. > > I can get what I hope is a good sight now > and then but find I need to carry far to many > books, almanacs and proformas > with me? > > By the time I have looked up the > information needed and filled in the proformas > everything is wet and falling > apart. > > I do sometimes take my laptop but battery > power is a problem. Can anyone tell me the best > system to use on a small boat > with limited resources on board > > (please don�t > say use a gps all the local boat clubs keep > telling me that. I have one but I want > to do it the proper way) > > Also is there any good share wear out > there that can produce daily tables (I have one > but it gives different results > to my yearly almanac). > > Thanks in advance > > > > > > Martin Hall > > Dave Weilacher .US Coast Guard licensed captain . #889968 .ASA certified sailing and celestial . navigation instructor #990800 .IBM AS400 RPG contract programmer