Are paper charts a dinosaur?

[jackdale]

In blue water, at the very least, one could resort to the Columbus technique - latitude sailing and DR.

[TeddyDiver]

Originally Posted by colemj

If an asteroid hits the earth, none of that will help you - or at least be of any relevance to you.

I don't think you fully understand the physics of an asteroid strike or the reason the question was asked of you (hint, think of relative probabilities for the last one).

Mark

Size matters in this case, small one being better

[colemj]

Originally Posted by TeddyDiver

Size matters in this case, small one being better

Placement matters just as much - a small asteroid in the wrong place being very bad

Mark

[TeddyDiver]

Originally Posted by colemj

Placement matters just as much - a small asteroid in the wrong place being very bad

Mark

Up in the space - good, down into ground - bad

[Dockhead]

Originally Posted by Adelie

As far as navigation goes:

Coastal I would carry large area chart(s) for the whole route planned, small area charts for intended destination and bailout destinations, pencil, compass, dividers, parallel rules, sextant, tables to use the sextant for range, binos and hand bearing compass.

Offshore I have a sextant, plotting sheets, parallel rules again, the Kolbe compact almanac and sight reduction book. I will be getting a metal box to keep 3-5 Casio Quartz watches plus 3 mechanical watches in. Watches would have their error rates logged. I am working on a spreadsheet to create almanac pages for the moon going out several years. These will be printed and carried.

Assuming a lightning strike where I lose everything including the watches and I have let the mechanicals run down and stop then:
Get the watches going
Determine approximate time from my DR and a noon sight. Or by using time of sunset and my DR.
Determine actual time shooting a round of stars and the moon. Then adjusting clock time forwards and backwards recomputing the fix until the moon line agrees with the stars. (This is the Letcher method for lunars, tedious but not very difficult.). Once the time correction for the watches is established I'd check it once a week or so but otherwise wouldn't need to reshoot the moon since I have reestablished accurate time.

Since I have cheap plastic sextant and compact tables & almanac this is not a "continue the voyage" system but a "get me into port for repairs" system.


Adelie

I respect this approach very much. I deeply respect the skill and preparation involved.

But it's not what I would do.

I keep various redundant satellite nav receivers on board. Two of them receive GLONASS as well as GPS (including the primary receiver on my network), in case there is any problem with GPS. One of these I keep in a metal box. I also have a few redundant chart plotters on board, including INavX on an IPad.

I keep a lot of paper charts on board, but they don't cover everywhere I sail.

I have nautical atlases and lots of pilot books on board which have the lat long of lots of ports, and chartlets of those ports and approaches. THIS IS IMPORTANT

I have hand bearing compasses and compass binoculars, and know how to do a three point fix, DR, and other basic navigation methods.


If I were offshore and experienced a lightning strike which took out all of my electronics, I would hope to have at least one satellite receiver which would give me a position.

But even if I lost all capabilities to get a satellite position, I wouldn't panic, and I wouldn't feel the need to do celestial. I would know out of basic situational awareness, and my log, more or less from where I am starting out, and how many miles in what direction is a likely landfall. I have a simple magnetic compass at my helm. I would head for my landfall and start DR. DR is pretty easy and pretty accurate if you have a working log. If the log is also fritzed, then it's harder, but I still know within a knot how fast my boat is going just by feel.

I would make my landfall, and if I have a paper chart of this place, then it's easy -- just navigate along the coast using three-point position fixes and regular position plots and go into port.

If there's no paper, there's still no problem -- I would just pick my way down the coast until I found a port. Then I would carefully observe the buoys and go in. I would watch the water and the depth sounder very carefully, and I would follow other boats if possible. If no depth sounder, I would heave to and wait and watch other vessels going in, until I felt sure about the right approaches to the port. I would also observe the foreshore through my binocs to understand the tides.

Basic navigation skills and basic seamanship are always necessary; electronics are not. Celestial navigation is also really not, in my opinion, however much I respect the skill.

[Adelie]

Originally Posted by zboss

a) Maybe but the new satellites are shielded. If that WERE to happen all society would break down cause it would also take out all the rest of our satellites, so I think we would have bigger problems.



b) In our lifetime maybe 1 or two satellites would get taken out. Bigger problems because this means we are at war with a big party - think world war.



c) This is why new GPS picks up russian, Japanese, to-be European, and American GPS systems. Besides, if it were hacked, you would not know until it was too late, even with paper charts... unless you were using a sextant.

A) western civilization would be disrupted but it would not necessarily break down. Even if it did I still would not want to die in place, I would want to get myself home and help fix things.

B). If there's a war where folks start popping off ASAT missiles they're not going to stop at 1 or 2 satellites, they're going to take down most or all the constellations. Even if they don't get all the satellites, below a certain number you can't get a fix. The current generation of receivers won't give you the hyperbolas of position when you can see 2 satellites so you can use that info to refine a DR and they certainly don't store the info for a running fix next time you can see 2 satellites. Perhaps military grade equipment does and possibly high end commercial but nothing I can afford.

Secondarily if a lot of ASATs are used then the debris generated will degrade or destroy what is left over time.

C). Anything bad enough to disable one constellation will probably knock them all out.

I didn't know the Japanese were working on a system let alone had one deployed. Or are you confusing the Japanese and the Chinese. They really are different ethnic and political groups and would appreciate being lumped together about as well as Russians and US citizens.

And yes I check the results of the GPS, most often using depths if there is a disagreement between depth sounder and charted depth for where GPS says I am then I start checking into why.


Adelie

[Adelie]

Originally Posted by colemj

If an asteroid hits the earth, none of that will help you - or at least be of any relevance to you.

I don't think you fully understand the physics of an asteroid strike or the reason the question was asked of you (hint, think of relative probabilities for the last one).

Mark

Oh I see, you made an oblique reference then used the fact that I didn't seem to get it to imply I was at least slow and ignorant and at worst stupid.


Adelie

[colemj]

A solar flare that takes out all the GPS systems would indeed end Western civilization because it would also be taking out every electronic circuit on earth. No food production, no distribution of any type, no communications, no monetary system, etc.

Horse and plow, seeds, gold or barterables - these will be all the useful things that remain. If you can find a plow and a horse willing to pull it.

You also don't understand just how difficult bringing down a satellite is by ASAT missile.

But to make the odds even more incredible in support of your argument, you assume you will be at sea, in open ocean, when these very improbable events occur!

This is silly speculation and silly reasoning in terms of the thread topic.

You really should be looking into that asteroid thing…

Mark

[noelex 77]

Originally Posted by Adelie

At some level I agree that there is fundamentally no difference between electronic and paper charts. At a usability level though electronic charts are entirely geared to position fixing via electronic means, and have no convenient means of permanently marking, labelling and storing navigation info from other sources.

It's not difficult to put "pencil" marks on an electronic chart.

The software will even instantly calculate the bearing of the line so there is less chance of mistakes.

Here is an example of a 3 point fix on an electronic chart. Easy.

Some traditional navigational technics are harder on electronic charts, overall I would prefer paper, but electronic charts are perfectly usable.

With the loss of the GPS satellites we are discussing a very unlikely doomsday scenario. Resorting to a back up system that is slightly less optimum is not a great concern.

[colemj]

Originally Posted by Adelie

Oh I see, you made an oblique reference then used the fact that I didn't seem to get it to imply I was at least slow and ignorant and at worst stupid.

It wasn't my reference and I didn't use or imply those words.

Mark

[Adelie]

Originally Posted by jackdale

I use OpenCPN to do traditional navigation. One circle of position is easy. For example if doing a fix on a Racon, draw the bearing / LOP and then measure the distance. I still use the route tool for that as it leaves a WP mark. Two COP's would be more difficult. But I will give that one some thought. Maybe a new feature request.

I often will do a set and drift when route planning from the comfort of my desk at home.

Here is a running fix that I did for a person studying for the ASA coastal nav exam. I used the route tool and reversed the route to get a reciprocal.



Here is one I did with labels - really the "proper" ones.

I can see you marked the lines using routes like I thought. How do you mark a fix? Any idea how to mark time and bearing values?



Adelie

[jackdale]

Originally Posted by Adelie

I can see you marked the lines using routes like I thought. How do you mark a fix? Any idea how to mark time and bearing values?



Adelie

I mark the fix by placing a waypoint and using a circle as an icon.

The time and bearing values can be added using the waypoint name of the waypoint properties. Check the show name box and they are visible.

BTW - you can also use different colours for each "route" / LOP to make it easier to distinguish between the course and the LOPs.

[jkindredpdx]

Wow! What a long thread. Only coffee, beer, or wine deserve a more heated and opinionated discussion... Oh hold on a second, thanks, sorry for the delay but my battery was going dead and I had to plug in... anyway IMHO, whether you use paper or not is a personal preference... so why feel compelled to prove the other guy wrong? I'd think the one thing we'd all agree on is there is no single right way. Is my antique Furuno, OpenCPN, and handheld GPS, compass, and paper chart system perfect? No! but it'll work for me until it doesn't and then I improve it.

[Cadence]

Originally Posted by Ann T. Cate

If the GPS system goes down a boat with paper charts is fundamentally no different to one with electronic charts. Both boats have lost their primary position fixing system, but both boats still have suitable charts and can continue to plot their position using traditional navigational techniques.

What a powerful argument for traditional navigation skills, sextant and all!

Ann

[colemj]

Is that your sextant timepiece in the lower corner?

Mark