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Thread: Navigation class recommendations?

  1. #21
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    Nov 2013
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    I enjoy celestial navigation and will be happy to discuss approaches toward a practical working knowledge. Sun sights (noon and running fix) are a great starting point. I also have an embarrassing number of sextants which im happy to show off. Steve dot hodges at cox dot net.
    I may email you with questions. So thank you in advance for your offer to help.

    I took a celestial nav workshop this weekend at OCSC taught by Paul Kamen. Poor Paul had a terrible cold and it was the first workshop they had run like this so it wasn't organized, but I got good practice with a sextant and a good working knowledge of noon sight for LAT/Long. My first sight was 30 minutes off, a whole diameter of the sun. The second was within 5 minutes, so practice helps.
    I did come to conclusion that it would take me about an hour or more to get my fix at sea, while down below, and pencil rolling off the nav desk, and trying to find my sight reduction tables, and drawing a straight line...
    Anyway you get my point. Thank "god" for GPS
    I would recommend the workshop at OCSC for anyone who just needs to brush up and dust off their sextant. Paul made himself available to answer any questions and is a very knowledgeable guy about sailing in general. I wish I had time to pick his brain. I'm sure as they have more of these workshops they will become better organized...and for $50 it's a good deal.

  2. #22
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    Quote Originally Posted by Steevee View Post
    I took a celestial nav workshop this weekend . I got good practice with a sextant and a good working knowledge of noon sight for LAT/Long. I did come to conclusion that it would take me about an hour or more to get my fix at sea, while down below, and pencil rolling off the nav desk, and trying to find my sight reduction tables, and drawing a straight line...Anyway you get my point. Thank "god" for GPS
    Deeply satisfying to advance LOP's and create a "fix."

    It is possible, and not difficult, to confirm LATITUDE up to 3x/day, without going below to get woozy, and doing addition or subtraction corrections mentally in the cockpit. I.E.: Dawn and dusk Polaris, and LAN (noon) latitude.

    With LATITUDE, and sailing from the east towards the west, as you will be, one can find Hawaiian Islands, Kauai, and Hanalei.... Navigators have been doing just that hundreds of years. Again, satisfying to be able to correctly claim, "oh, we used the sun and the stars to help find our way to Hanalei Bay..."

    And don't forget the Polynesian voyagers' bright star above Hawaii = Hokule'a

    Same thing sailing east to latitude of mainland home port.
    Last edited by sleddog; 02-08-2017 at 12:47 PM.

  3. #23
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    "It is possible, and not difficult, to confirm LATITUDE up to 3x/day, without going below to get woozy, and doing addition or subtraction corrections mentally in the cockpit. I.E.: Dawn and dusk Polaris, and LAN (noon) latitude"

    Definitely true! Once you 'get it down' the whole process from sight to LOP or fix takes a few minutes (<30) and involves simple arithmetic. Here's an example of a noon sight reduction done under way last summer. The noon sight starts with the tabulation (GHA and Dec for 2200 and 2300 UTC from the nautical almanac): https://goo.gl/photos/HUesVeVomgZqNU3N8

    There are conditions which might make this process more difficult but Frank Worsley showed that celestial navigation was possible even in extreme situations.... but Worsley was an amazing man!

    http://www.sebcoulthard.com/navigati...struments.html http://www.archive.jamescairdsociety...ting%20med.jpg

  4. #24
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    With LATITUDE, and sailing from the east towards the west, as you will be, one can find Hawaiian Islands, Kauai, and Hanalei.... Navigators have been doing just that hundreds of years. Again, satisfying to be able to correctly claim, "oh, we used the sun and the stars to help find our way to Hanalei Bay..."
    Yeah, I figure if all the satellites fall from the sky or if there's some kind of geo/politcal event while I'm 1000 miles from nowhere I could find latitude and sail straight up on the beach somewhere along the Hawaiian island chain. Coming back would be even easier. The North American Continent is Yuuge.

  5. #25
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    Definitely true! Once you 'get it down' the whole process from sight to LOP or fix takes a few minutes (<30) and involves simple arithmetic. Here's an example of a noon sight reduction done under way last summer. The noon sight starts with the tabulation (GHA and Dec for 2200 and 2300 UTC from the nautical almanac): https://goo.gl/photos/HUesVeVomgZqNU3N8
    Thanks for the sight reduction problem. I found these really helpful. I picked a celestial navigation workbook title, "Miranav" by Rosalind Miranda and found it very helpful especially after taking that class. It definitely takes practice to get proficient. It is satisfying when your numbers work out.

  6. #26
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    Quote Originally Posted by Steevee View Post
    I picked a celestial navigation workbook title, "Miranav" by Rosalind Miranda and found it very helpful especially after taking that class.
    There are any number of excellent primers on learning celestial nav...My favorite is fun to read, easily understandable, and takes you along on a voyage/race to Hawaii using only celestial. It is titled Celestial Navigation by H.O. 249, by John "Stu" Milligan, published by Cornell Maritime Press.

    It would be a fun exercise to lock the GPS in a box onboard, and sail to Hawaii using DR, and celestial. You would likely make your landfall quicker, and more comfortably, than using GPS, which leads you astray if using Great Circle sailing.

    Great Circle sailing to Hawaii opens the likelihood for the unwary of sailing slowly and too close to the wind in Windy Lane. Then, on the average year, using GC sailing, you sail into the calms of the EPAC High, similar to what happened this past summer in the SHTP, though not in the Pacific Cup.

    My father, the Honolulu Race fleet weatherman aboard the record breaking 98' schooner MORNING STAR, in 1949, helped pioneer the "Reverse S" course to Hawaii. The "Reverse S" course takes you initially reaching SW, under the Pacific High, then gradually sailing West until jibing onto port for Hawaii.

    The Great Circle to Hawaii, as provided by GPS, does the opposite.

    Caveat Emptor

    Here is one of my father's weather maps presented to the '49 Transpac fleet at their pre-race weather briefing. Some disregarded and sailed straight for Hawaii, much to their later chagrin They radioed the fleet on days 4-7, "glassy calm, we are racing our garbage." (This on a then pristine Pacific Ocean.)

    Name:  ReverseS 001.jpg
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    Last edited by sleddog; 02-09-2017 at 10:42 AM.

  7. #27
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    May 2016
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    Berkeley
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    Here's something that looks like a great resource for learning celestial navigation: http://www.practicalnavigator.org/

    It's put together by a former Coast Guard commanding officer and features a deep list of videos:

    http://www.practicalnavigator.org/ge...avigation.html
    http://www.practicalnavigator.org/go...avigation.html
    http://www.practicalnavigator.org/ad...avigation.html
    http://www.practicalnavigator.org/ce...cuttermen.html

  8. #28
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    Montara, CA
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    Great thread; cool family history, Sled!

    I've got The Book (Dutton's) and have been thinking about learning celestial navigation for a while now, but don't have a sextant yet. What's the consensus on that? How much difference in quality and accuracy is there in buying one for around $200 versus $2000?

  9. #29
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    I don't see a reason to pay more than $500 for a sextant. My favorite sextant is a WWII Navy Mark II (David White) which i paid a few hundred $ for about 15 yrs ago. You can still find very nice sextants online, for far less than $2k, for example, this Simex for ~$500:

    http://www.ebay.com/itm/Vintage-Mari...-/112293681552

    Of course you can buy a new celestaire for about that - but they aren't the same. And though they can be made to work ok, i don't like the plastic ones (they drift a lot).

    The advantage of the oldies is they are generally very well made, and they hold their value. A possible disadvantage is that you may have to clean and adjust before it is usable, and you might need to find the special tool to do so; but i think, in the spirit of self-sufficiency, those are actually advantages.

    A good book on buying and maintaining sextants is 'The Sextant Handbook' by Bruce Bauer

    https://www.amazon.com/Sextant-Handb.../dp/0070052190

  10. #30
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    Quote Originally Posted by Gamayun View Post
    How much difference in quality and accuracy is there in buying one for around $200 versus $2000?
    A plastic sextant is fine for learning, and general use. A drawback is they seem to warp, shrink, and expand in warm tropical weather or bright sunlight, needing new correction each time of use. No biggee, but time consuming. Their scopes are also not very good for stars.

    Of course the Plath remains the gold standard in sextants. But they are heavy (bronze) and most don't have the full horizon mirror. A bronze sextant is tiring to hold up to the eye for any length of time.

    An aluminum sextant is less than half the weight of bronze. I had an aluminum Freiberger (Zeiss Instrument), made in East Germany, with a full horizon mirror. It was the cat's meeow. Sold it for $500 on CL to float the boat. Sigh.

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