NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Slip + 1st Lunar
From: Doug Royer
Date: 2003 Apr 25, 12:20 -0700
From: Doug Royer
Date: 2003 Apr 25, 12:20 -0700
Thank you all for your suggestions and advice on the Lunar.I really appreciate the help.I'll be useing all the advice and tips given.I'm going to go ahead with it this weekend.That said,however,I'm going to take Mr. Prinz's advice.I think doing it in stages as he advises makes perfect sense.I'll start out practiceing takeing the angular measurements between the differant bodies throughout the day on Sat.Sunday I plan to practice useing the horizons on as many bodies as I can.This 1st weekend I am interested in only honeing the mechanical techniques and my skill level(speed of multiple accurate measurements). I live at roughly 33.0* N and 116.7* W.The 1/4 moon can be seen the last few days untill about 0740 zt.In fact I was out this morning at 0650 zt (that was when the sun's upper limb came into veiw)and practiced takeing the angle between the moon and sun.The moon's image is fairly washed out by then and hard to get a good reading.I'll get up early in the morning to practice in darker conditions. I'll be useing my Tamaya with no more than 6x.I'll start out useing the 3x.I have 2 horizons;a Davis and 1 I made a couple of weeks ago.The Davis has plastic sheilds and the one I made uses glass.I'm looking forward to mastering this technique(over time).Mr. Pearson, I'll get to your website shortly after sending this. Let's put this slip thread to rest.Mr. Prinz,the exam questions are in sections.I wrote it out exactly as on the exam.One question may be as I wrote it and the next question may be about ship's stability.The examiner,when questioned about it,showed me that in the study material statute miles are used and that is what was the expected answer.Details,he said,pay attention to details.That in itself was a lesson. No,they're not really used.I would use a preobserved speed card(graph).GPS and Doppler are now used for this and calibrateing equipement.That said, if all else fails, I would know how to use the proceedure and that is what I believe the C.G. was after. Basically,useing this example, this is how calculations are used on board: At a certain vessel speed it is known that the rpm's of the plants and shafts should be certain quantity;takeing into account ship's draft,precalculated fuel consumption and other ship's factors.If the calculations are in the "ballpark" with other data,than all is fairly well.If not,on the other hand,you had better find out why.Could it be damage to something,equipement that needs calibrateing,excessive bottom fouling or just a sloppy set of calculations?Find the problem and correct it at the earliest opportunity etc.It's just a piece of the whole puzzle so to speak.