Perhaps this subject has arisen before, however it might shed an interesting light on choice.
Given the fact that in this day and age we have the absolute best navigation tools ever devised, we, as purest CN lunatics, long for technology of bygone days - nevertheless we still welcome the chronometer as a standard piece of gear.
Granted the chronometer greatly improved the accuracy of early navigators, Slocum - unable to afford one - used an old tin clock. So how did he navigate? There was no WWV or radio beacons, etc. The answer - The lunar method. He didnt need a chronometer, and although a goat ate his charts, he made the trip without much difficulty. Of course the lunar method is more cumbersome mathematically than our present day single shot table methods, but he still needed a sextant - and circle the globe he did. HOW COOL IS THAT? I once (ignorantly) used nothing more than a road map to navigate the great Yukon River in Canada by canoe. The HMS Bounty captain, after mutiny, had but a very limited supply of NAV tools to usher his surviving crew thousands of miles to safety - avoiding known islands of inhospitable natives - without chart table or enclosure within to work.
My question for you: What is the absolute minimum navigational equipment list and navigation technique you might feel comfortable with if circumnavigating the earth solo or with a minimal crew? (include any and all paper references, tools, recording implements (pencils etc.), space requirements, support equipment (table, chart room, etc), and lighting. Exclude supplemental emergency devices or implements.
Have fun
joe
Joe,
I love this kind of question and the statements you made. Road map?! Wow! Now THERE'S and adventurer!!!
Lunar method would be the end of my cel nav work and it's certain it would burn me out. On the other hand, in the book, "Carry on, Mr. Bowditch" the entire crew of one of the ships he was on could do Lunars, he taught them.
I maintain that the mathy types have wrecked so much of astro-navigation methods making it confusing and more "why" instead of "how".
For me the simplest celestial navigation kit would be;
- Sextant (Astra III-B)
- Chronometer- Columbia watch
- Grundig Yacht Boy SW radio to get time signals when chronometer is in doubt.
- The Nautical Almanac (for the years of the voyage) with associated documents (corrections & increments, Altitude Correction Table)
- USNO Navigational Star Chart
- Pub.No. 249 Vol 1 and Vol. 2....maybe Vol. 3 also
- Casio calculator
Plotting;
- Small plotting table (a simple 24" square board) I always plot with the board this way and no navigation station
- A red colored head lamp or stationary light
- HUGE pile of white erasers
- Mechanical pencils and lead- .07mm
- Sun, Star & Planet sight reduction forms in a notebook (from this site)
- UPS sheets
- parallel rules
- dividers
- Scotch tape
For an absolute minimum?
- Sextant- Astra III-B
- Chronometer as listed above
- TABLE 4- GHA and Declination of the Sun for the Years 2001 to 2036
- TABLE 4- Long Term GHA Aries
- 2018 Navigational Stars SHA & Dec (for years beyond 2018 the SHA and declination don't change very much)
- Altitude Corrections for the Sun, Moon, Stars and planets
- Increments & Corrections (yellow pages)
- USNO Navigational Star Chart
- Casio calculator (several spares) in which case I wouldn't need Pub. No. 249 at all.
Plotting tools- same as above
Now, when do we set sail?
Roland
(06-23-2018, 10:17 PM)Rdutton Wrote: [ -> ]For an absolute minimum?
- Sextant- Astra III-B
- Chronometer as listed above
- TABLE 4- GHA and Declination of the Sun for the Years 2001 to 2036
- TABLE 4- Long Term GHA Aries
- 2018 Navigational Stars SHA & Dec (for years beyond 2018 the SHA and declination don't change very much)
- Altitude Corrections for the Sun, Moon, Stars and planets
- Increments & Corrections (yellow pages)
- USNO Navigational Star Chart
- Casio calculator (several spares) in which case I wouldn't need Pub. No. 249 at all.
Now, when do we set sail?
Roland
Good Show Roland... now that's the spirit.
I have yet to decide on method and tools. I think though that my list might be shorter and less technical than your list. I am still looking at Ageton's method to reduce paper, and alternatives to the sextant (such as modified Gunter's quadrant with which Ive had much success and might learn to trust on a long voyage.) I did not notice any charts in your list. I too am undecided as to which type of chart and how many - perhaps as an absolute minimum the gnomonic projections or great circle charts covering large areas would do and a few local charts of dangerous areas (great barrier reef) and planned ports of call. I am decided on space in that I would need absolutely an enclosed cabin within which to work the observations - however I think i could do without electric lights or calculators. I might even limit myself to sun observations thus reducing more paper... Your table 4 choice is spot-on... How about depth determination and ship speed - what equipment would you choose? or would depth and speed not be important for you; and what about a compass?.... I once read an at-sea account that indicated ships passing would frequently speak and share data such as position and clock readings thus helping each captain verify position records and chronometer settings... of course the worlds oceans are not as congested as they once were.... more later.
joe
Joe,
You're right- I forgot charts. A gnomonic would be a good idea or just a Mercator to mark the course traveled. An electronic knot meter might be best instead of a Log (thrown overboard and retrived). The knot meters that are towed often get devoured by creatures of the sea. Maybe I'd just use an hourly estimate of speed using this formula;
(Boat Length ÷ 6076) x (3600 ÷ Seconds)= Speed
Once you figure out the time in seconds as it applies to speed you can put the figures on a card and then time bubbles off the bow passing from bow to stern.
Yes, I'd use an electronic depth sounder around coastal waters but shut it off once at sea. Casting the lead isn't something I've been able to do well when trying to sail.
General charts of the ports-of-call would be sufficient. Years ago I found a site that had them for free (electronic) but I've since forgotten where the site was.
Roland
So I finally accounted for the minimum tools I use during a CN Sun shot and wrote them down MOSTLY in order of use. Where applicable I included in (parentheses) alternate tools that would be just as useful. Of course some of these tables can be replaced by calculation, but if I could only choose one method I would choose water-proof paper tables.
Pencil
Paper
Watch
Timer
Seaman's astrolabe (Sextant)
Electronic calculator (Abacus, and slide rule)
Current Almanac Sun (Table 4)
Increment table
Chart
Pub 249 (calculator)
Table 5 (math alternative)
Dip table
IE data
Altitude correction table
My personal Proforma
Plot table
Plot sheet (or plain paper to create plot sheet)
Tape to secure plot sheet to board
Pencil sharpener
Protractor
45 degree triangle
30/60 triangle
12 inch ruler
Eraser
Dividers
Compass with pencil
How does your minimum equipment list stack up? Of course on the boat Id want a ships magnetic compass and hand compass, some kind of depth finder, chip log or equivalent, some kind of light, work space, and backup supplies. I think I would also want almanac tables for all bodies. If I had a lot of time at sea Id study the lunar method and start practicing.
Joe