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Old 12-16-2012, 10:58 AM   #21
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Greetings: Perhaps you misspelled the word "dead". It should be "ded-reckoning".
It was 'Dead Reckoning' in all of my military training.

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Our navies now rely on electronic devices and have even done away with Starboard and Port. Right/Left.
That's not true at all.

I've barked bridge orders many many times. You NEVER turn Port or Starboard... you turn Left or Right. But... you can actually use both terms at the same time. (usually to confuse a young Officer.

ex: "Helm... Left full rudder... Hard over to port... Steady up on course XXX"
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Old 12-16-2012, 11:15 AM   #22
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Back in our sea kayaking days I absorbed everything I could from the first edition of, "Fundamentals of Kayak Navigation" by David Burch, who is the Director of the Starpath School Of Navigation, a school geared towards motorized and sailing vessels.

Fundamentals Kayak Navigation 3 - David Burch - Google Books

Using his knowledge as an instructor of navigation courses and his experience as a sea kayaker, he explains how to navigate with basically a watch, a chart, a deck compass, and a kamal. (It's been years, but a kamal is a small notched stick held vertically and kept a known distance from your eye by a string with a knot in the end that is held in your teeth...this allows you to find your distance from mountains of known elevation.)

Sort of like a bush pilots understanding of navigation as compared to a passenger airliner pilots use of navigation.

If you want to learn how to truly navigate by the seat of your pants, this book comes highly recommended.
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Old 12-16-2012, 11:16 AM   #23
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Capt Rigney said:
"ded reconing"

I googled this and it said "Do you mean Dead Reckoning."

Aside from the fact that we can all agree on using charts, compasses, Mother's apple pie is the best etc, I am reminded of a visit I made to Greenwich England a few years ago to visit the time museum. Hundreds of years ago "Old timers" argued about the accuracy of new fangled time and star measuring devices. Then they argued about how to measure ship speed. The new technology guys went a long way (read about Capt Cook or George Vancouver) during their era, largely motivated by cash prizes, titles and recognition. This dedication to the old stuff will never stop, it is the nature of man and why we finally peter out with the new guys take over.

Think Steven Jobs, Apple, IPad, Navionics and usability of same being discussed on another thread.

PS I have about 150 charts for the PNW alone and storage is a huge issue, any suggestions?
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Old 12-16-2012, 11:21 AM   #24
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I was schooled in the "ded" camp. But, as always, there is usually 2 sides to every story. The following link is to a site called the Straight Dope. It may or may not put the subject to rest, but is an interesting read:

The Straight Dope: Is "dead reckoning" short for "deduced reckoning"?

The next to last paragraph has some good advice for forum dwellers that applies to more than this discussion:

Some feel compelled to "correct" people who write "dead" and not "ded." Obviously I don't believe they should, but it might come as a surprise to some to learn that neither does the FAA or the Coast Guard. A search of their websites finds zero references to "ded" or "ded." or "deduced" reckoning, but quite a few references to "dead reckoning." In practice, the term is usually abbreviated DR, which is probably safest if you don't want to get into an argument.
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Old 12-16-2012, 11:21 AM   #25
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PS I have about 150 charts for the PNW alone and storage is a huge issue, any suggestions?
Many artists are searching fo them. They use the old ones for backdrops for shadow boxes and the likes. Old charts are cool for that sort of thing. Also, your local Power Squadron or other may take them for training. They like it wne students can mark them up.
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Old 12-16-2012, 11:23 AM   #26
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It may or may not put the subject to rest, but is an interesting read:
Good link, Thanks.
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Old 12-16-2012, 11:27 AM   #27
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Old 12-16-2012, 11:47 AM   #28
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A Haisla friend of mine (First Nations people from the head of Douglas Channel on BC's north coast) told me about how him and a friend got home one winters night, back in his high school days. It was in a small outboard boat, at night, in a snow storm. They had nothing, not even a flashlight.

His friend had grown up in boats and on this part of the coast. Apparently, they made it home by recognizing changes in wave patterns (rebounding off distant rock walls, refracting off shorelines in the dark, or areas where waves from several angles met...like when waves cross each other after tear dropped shaped islands) and by yelling at the shore to listen for their echos.

My friend, who doesn't have much experience on the water, was amazed they got home alive.

Oh, and before anybody jumps on them for doing this, remember all the things you did as a teenager that in hindsight you were lucky to survive?
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Old 12-16-2012, 11:49 AM   #29
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Old 12-16-2012, 11:50 AM   #30
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As an aside, I was helping a pal lay out a log race on Lake Michigan, just off the city of Chicago. The race went from one "crib" to another "crib." We are in San Diego and did not know what a "crib" is, although they are on the chart. It seems a crib is a man-made structure housing a pipe that draws off lake water for use ashore. As they say in Brooklyn, "You live and loin."
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Old 12-16-2012, 12:17 PM   #31
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I have some issue with the statement "First, a definition is in order. Dead reckoning is the process of estimating the position of an airplane or ship based solely on speed and direction of travel and time elapsed since the last known position (or fix). So all you need to figure out approximately where you are is an airspeed indicator or log or other measure of speed, a clock or watch, and a compass."

I was taught DR was the initial 'plotting' of a course. You grab a chart, mark off your current position and your intended destination. Draw a straight line between the two and you should be able to determine your course and diatance. Once underway, you can calculate your ETE for any given speed. DR does not take into account things like wind speed and current. That is DR - plain and simple. With DR, your course and heading are the same - which rarely happens in the real world unless on a small lake with no wind or current
Once you start accounting for 'set and drift', you are no longer DRing. You are navigating by known parameters.
Anyway, this is what I was taught in Sea School in the land that time forgot.
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Old 12-16-2012, 01:56 PM   #32
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TonyB you are quite correct in your take on what a "DR" and its use. The other side, taking fixes to prove your closeness to the intended course and destination requires the deduction. Now to another issue.
TVMDC: Jeffnick used the more common, but bear with me for a minute. I taught CPS courses in Ottawa for years and still do. However during the session on compasses and the issues of bringing that reading to the chart I used the old "True Virgins Make Dull Company" and "Can Dead Men Vote Twice". All is the class seemed to have gotten the point, but at the back of the class sat two ladies, both quite good looking, one a blonde, she had her hand up. So I asked her if she had any difficulty. No was her answer, but she felt that "Tired of Male Derogatory Comments" would be a better way to remember TVMDC.
A number of years ago I had the oppertunity of going from Cape Town SA to Tilbury UK. Each hour the bridge officer confirmed our position from three GPS units and using speed/time did it manually on a paper chart with the course laid out and DRs at the supposed hour location.
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Old 12-16-2012, 02:27 PM   #33
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Doesn't anyone believe SPY when he says what you are talking about is called "pilotage?"

Good grief, look it up. Dead reckoning is based on heading, speed, and time, not landmarks.
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Old 12-16-2012, 02:44 PM   #34
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I do carry paper charts for the areas I travel and I always track my position on the chart plotters and confirm it visually. In the delta, the fog can form quickly and in pockets, so those old forms of navigation on the serpentine rivers and shallow sloughs can be inadequate.
This is in essence what we do and is why we always follow routes we have put on the plotters and have the radar on even when the visibility is excellent.

While we don't have the frequency of localized fog that seems to be characteristic of SFO Bay, we can get it during certain parts of the year. At those times it's not uncommon to be running along in bright, clear weather and come around an island to be confronted with heavy, low fog in the next channel we have to traverse.

We both feel that by using the plotters and radar on an all-the-time basis it makes it a lot easier to transition to the "instruments" when we need to. But we use the paper charts (and now the iPad with the really good Navimatics chart application on it) to confirm our position and what's around us regardless of the visibility.
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Old 12-16-2012, 03:06 PM   #35
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PS I have about 150 charts for the PNW alone and storage is a huge issue, any suggestions?
Well, we don't have 150 charts. Maybe twenty or thirty for the waters from the San Juans up through Desolation Sound which is as far as we've taken the GB so far. (We go farther north with the trailerable Arima).

We keep our charts rolled up, usually two or three to a roll, and stored on top of the closet in the aft cabin. I keep meaning to make a rack for them--- two vertical, teak "bulkheads" spaced apart with holes for the map rolls-- but so far have not gotten around to it. One could also make the same sort of thing for vertical storage of charts in a closet or wherever as long as there was the necessary headroom available to pull them out of the rack.

For everyday use we have the big chartbooks for the San Juans, Gulf Islands, Sunshine Coast, and Desolation Sound. They sit on a modified MapTech chartboard next to the helm console (photo).
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Old 12-16-2012, 08:27 PM   #36
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Yes, it has always been dead reckoning for mine...
I have always assumed it related to the fundamental accuracy required in the various course, speed and elapsed time parameters, to be absolutely spot on to be correct - which of course they never can be - or you were dead wrong, in effect. Maybe the concept has the same origin as the old saying one gave to a marksman, he's a "dead eye dick', because for dead reckoning to be accurate, the speed, course and time needed to be 'dead' accurate. Of course inaccuracy of instruements like clocks, compasses, and tidal movement make the above impossible, so one could therefore extract the inference that if you rely on dead reckoning for more than a brief spell, you might end up 'dead'.
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Old 12-17-2012, 06:21 AM   #37
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Can Dead Men Vote Twice ?

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Old 12-17-2012, 06:31 AM   #38
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Someone else mentioned those two mnemonics FF. What do they stand for? I suspect we have different ones for the occasion.
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Old 12-17-2012, 08:42 AM   #39
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Someone else mentioned those two mnemonics FF. What do they stand for? I suspect we have different ones for the occasion.
T=True
V=variation
M=Magnetic
D=Deviation
C=Compass

And vice/versa
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Old 12-17-2012, 09:31 AM   #40
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The 'Add Whiskey' mnemonic is to remind operators to ADD Westerly correction and SUBTRACT Easterly when correcting for magnetic deviation. This is needed when converting from true to magnetic or magnetic to compass.

I was a Antisubmarine Warfare Tech in the Navy and flew / operated a piece of gear early in my career called a 'Nine Term Compensator' and your whole flight was spent trying to keep magnetic deviation nulled out. It was a real chore at times.

It became automatic a few years later and my life got a lot simpler.
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