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Hi Shipmates,


I've got some more practice data for you. I've calculated it already; it provides acceptable accuracy:  +- 2 miles

Point one:  For the last month I've allowed my chrono to wander off-time to see where it goes and determine the rate.  I've calculated the error as plus .181 seconds a day.  So taking the daily error into account I had to subtract 7.5 seconds from my observation time.  You must do the same.  So when you average the following sets of observations remember to subtract the watch error.  

Point two:  In my part of the world GMT changed to a new day so please examine the dates carefully... you will have to use a different date for each set of observations.

I made an initial math error of one digit (10 minutes) that threw off my first lops by about 12 miles.  After finding the mistake my lops landed just where they should... My suggestion:  check your figures and math carefully.

Point three:  Remember these observations are in the Eastern Hemisphere and the sun is in the Southern hemisphere.

The earlier observations were taken in clear skies, however, the ones taken later were a bit staggered due to the formation of cumulus clouds which covered about 40 percent of the sky.  The difference in Z is only 30 degrees but that seems enough in this case for a good fix.  Have fun.

Nov 24 GMT

HHMMSS    DDMM.M
233849      2455.6
234027      2516.4
234138      2532.5
234255      2548.0
234405      2603.2

Nov 25 GMT

021451      5337.8
021653      5352.4
021953      5414.0
022044      5421.4
022153      5429.2

eye height = 15 ft
index error = 0
body = sun LL
DR = 10 N  124 E

Here's the GPS location just to see how far you're off: 10:14.54 N   123:57.4 E

Please be advised that this is my last attempt to share my experiences with you...  Most of you haven't the interest to explore this hobby with me, thus, I'm compelled to seek new friends on another board - this one seems practically dead, I'm sorry to say.  In this day and age of the effortless instant email Im much surprised at the lack of interaction.

My sincere respects and appreciation to Capt. Diego Melas for his kindness and generosity.  Diego is a fine Italian man who gave me a perfectly wonderful sextant to enjoy, and who has shared his family and his love of Christ with me and mine.  I now consider him a friend.   

I also thank the few members and ADMIN who have sometimes responded.  For those who wish to communicate with me just send a private message - I will check for mail infrequently but would be happy to correspond with those who have interest.
 
Cheers  

Sorry to see you go. Sadly, modern life has a way of getting in the way despite innovations in communications. In days past a letter in the mail would have been treated and responded to with more gravity.

(11-26-2018, 05:32 AM)pabrides Wrote: [ -> ]Hi Shipmates,


I've got some more practice data for you. I've calculated it already; it provides acceptable accuracy:  +- 2 miles

Point one:  For the last month I've allowed my chrono to wander off-time to see where it goes and determine the rate.  I've calculated the error as plus .181 seconds a day.  So taking the daily error into account I had to subtract 7.5 seconds from my observation time.  You must do the same.  So when you average the following sets of observations remember to subtract the watch error.  

Point two:  In my part of the world GMT changed to a new day so please examine the dates carefully... you will have to use a different date for each set of observations.

I made an initial math error of one digit (10 minutes) that threw off my first lops by about 12 miles.  After finding the mistake my lops landed just where they should... My suggestion:  check your figures and math carefully.

Point three:  Remember these observations are in the Eastern Hemisphere and the sun is in the Southern hemisphere.

The earlier observations were taken in clear skies, however, the ones taken later were a bit staggered due to the formation of cumulus clouds which covered about 40 percent of the sky.  The difference in Z is only 30 degrees but that seems enough in this case for a good fix.  Have fun.

Nov 24 GMT

HHMMSS    DDMM.M
233849      2455.6
234027      2516.4
234138      2532.5
234255      2548.0
234405      2603.2

Nov 25 GMT

021451      5337.8
021653      5352.4
021953      5414.0
022044      5421.4
022153      5429.2

eye height = 15 ft
index error = 0
body = sun LL
DR = 10 N  124 E

Here's the GPS location just to see how far you're off: 10:14.54 N   123:57.4 E

Please be advised that this is my last attempt to share my experiences with you...  Most of you haven't the interest to explore this hobby with me, thus, I'm compelled to seek new friends on another board - this one seems practically dead, I'm sorry to say.  In this day and age of the effortless instant email Im much surprised at the lack of interaction.

My sincere respects and appreciation to Capt. Diego Melas for his kindness and generosity.  Diego is a fine Italian man who gave me a perfectly wonderful sextant to enjoy, and who has shared his family and his love of Christ with me and mine.  I now consider him a friend.   

I also thank the few members and ADMIN who have sometimes responded.  For those who wish to communicate with me just send a private message - I will check for mail infrequently but would be happy to correspond with those who have interest.
 
Cheers  

Sorry you've decided to go. I don't think this site is dead. There is ton of information and a lot of discussions concerning problems of different levels. It looks like you are a very experienced navigator and maybe because of it some discussions or "revelations" bore you. Just my guess. Happy sailing.