Paper Charts and Electronic Wonders

[Bill Michne]

I'm late to answer on this one so I'll just unload all the information at once. We have a chart plotter at the helm that is always operating, and a handheld chart plotter as backup. We also have operational loran on the boat. Do I keep a DR on a paper chart? Of course, because high tech stuff, nice as it is, can and does fail, usually when needed the most (Mr. Murphy is very clear on this point). When keeping a DR the only thing likely to break is the point of my pencil. We keep two sharpeners on board. Of course, all this applies to longer trips. I don't keep a DR for a short local hop to a favorite lunch stop.

The same is true for a log. We like to go back sometimes and read the entries for our longer trips (...winds 30 knots, seas 6-8 feet, crew barfing in cockpit...). I also keep a maintenance log so I can keep track of when the yard operator needs to make his kid's next tuition payment, etc.

We also have radar on board, with the screen visible from the helm. We have never used it in fog, but always had in on during night passages in LI Sound and off the Jersey coast. We don't sail much at night any more, but when we do the radar is on.

All kidding aside, the bottom line on all this is that the single most important bit of navigational equipment is located betweeen the skipper's ears. There isn't a single bit of navigational technology, down to and including the pencil, that will save your boat or your butt if you don't know how to use it. People do incredibly dumb things. I just heard of a guy who tried to sail his 55' mast at hull speed under a 45' bridge that he thought was a 65' bridge on the ICW. He obviously didn't even know he was lost!

[j2sailor]

Thanks for the fabulous input. I’ve consolidated some of your responses and established the following. Please feel free to respond with additions or suggestions for change. Thanks again...

1. Cape Dory owners are very much “ahead-of-the-pack” in knowledge, maritime education and the practice of good seamanship.

2. Most CD owners still carry paper charts and intend to continue this practice.

3. In general, CD owners do not actively plot positioning information on their charts, yet have the knowledge and confidence to do so whenever necessary.

4. Many owners keep a basic log of courses, speeds, distances, soundings and engineering data. The log becomes more important during transits of unfamiliar waters.

5. Visual-navigation, reference to a chart-plotter or GPS with integrated mapping-feature, integrated or stand-alone radar and fathometer make up the primary day-to-day navigational tools under sail or auxiliary power.

6. Paper nautical-charts today are used for…
• Backing-up ENC or GPS navigation systems
• Establishing the “big-picture” of an unfamiliar area prior to or during transit.
• Voyage or cruise planning and provisioning estimates.

7. Additional reasons CD sailors continue to use paper nautical-charts
• Electronics used in the marine environment are prone to failure.
• ENC displays are limited to the size of the viewing screen.
• Zooming-out presents only a very small-scale thumbnail view – impractical for most long-range cruise preparations.

[Joe CD MS 300]

I'd disagree on one item, the first in item 7. I don't think that marine electronics are "prone" to failure. They can fail but I believe that it is relatively infrequently. You need to be prepared for a failure at any time but I have only experienced two instances of a failure with radar or GPS units. One, my handheld GPS screen went bad while in the BVI's on a charter and the second when one of my kids kicked a cable connection for the radar loose up in Maine. All in all they are pretty good in my opinion but you need to be prepared in any case if they do go down at the worst possible time.


With the new combo units, radar & GPS chartplotter combined you need to have a backup stand alone unit or a handheld just in case in addition to the paper charts.

[John Vigor]

Great summary, j2 sailor. You're going to make Cape Dory sailors famous. What's the book called, who's publishing it, and when can we buy a copy?

Cheers,

John V.
______________

From Vigor's Rules for Life:
2. The Golden Rule: "Whoever has the gold makes the rules."

[Joe Myerson]

One more comment on my logbook, which is also, of course, a record of maintenance (and record of engine hours), as well as a journal of days spent on the water.

I've only had to invoke its status as a legal document once, when dealing with a marina (you know which one, Neil). I had reserved for a specific length of time, but ended up leaving a day early. I notified the office and turned in my key early.

However, the change was not reflected in my bill. When I complained to the person who kept the books, he said he would need proof that I had left earlier than originally planned. I told him that I kept a logbook, and invited him to inspect it. He never asked to see the log, and six months later I finally got credit for the change.

--Joe

[Tom Keevil]

Does everyone really have a chart plotter on board? We don't, and we use paper charts for our navigation. A good part of the fun of sailing is figuring out where we are, and where we should go. That means that we are relatively conservative in our choice of routes, but that doesn't seem to be a bad idea. We've run aground by actually believing the data on charts (check the chart to see when the soundings in those back sloughs were measured - you may be surprised how little of your tax dollar is spent there). When using paper charts you must maintain a constant situational awareness - again not a bad thing.

We do use three electronic aids to help confirm our positon and provide essential information in poor conditions.

1) a depth sounder
2) a radar, which tells us not only where we are (if we're close to land), but who else is out there moving around. This is important for the foggy northwest coast.
3) a rather ancient handheld GPS without any charting capability. We enter waypoints such as the sea buoy of the harbor we're headed for. This provides an easy check on our course and our progress. The GPS also interfaces with the radar to help sort out targets - it will identify the position of a waypoint.

[joeeb]

I would be interested in hearing from members why the sextant has been relegated to the endangered species list.

[John Vigor]

joeeb, you might as well ask what happened to the astrolabe, the quadrant, the cross-staff, the backstaff, the traverse board, the octant and many other navigation instruments that were extremely useful in their time.

The fact is, their time has gone. It's called progress. Of course you can still use a sextant if you want, but why a sextant? Why not an octant or a backstaff? Lots of fun, the backstaff. What's a sextant got that the backstaff hasn't? Why the bias?

Incidentally, have you tried to use a sextant at night? In the fog? In cloudy weather? In snow? In a storm at sea? GPS can give you a position fix (and much more) in an instant under all these conditions. With the push of a button it made the sextant obsolete.

Well, all right, I'll admit there are some of us who actually think taking a sight with a sextant is fun. We kid ourselves it connects us directly with long generations of seafarers, and makes us better sailors. Sometimes, when an easy noon sight confirms our latitude on the coast it may indeed actually be useful. But we're really just playing at being Luddites and pretending we're more knowledgable than other skippers, and therefore more desirable to the hot chicks in the yacht club bar.

After one race across the Atlantic, I was invited into the cockpit of the big Boeing bringing me back home, and lo, there was a dedicated navigator taking sextant sights in a special little bubble dome. The year was 1971. How many dedicated aircraft navigators do you suppose there are these days; and how many use sextants?

Cheers,

John V.
_____________________

From Vigor's Rules for Life:
3. Hartley's Second Law: "Never sleep with anyone crazier than you."

[Didereaux]

joeeb, you might as well ask what happened to the astrolabe, the quadrant, the cross-staff, the backstaff, the traverse board, the octant and many other navigation instruments that were extremely useful in their time.

For starters, the sextant is magnitudes more precise than any of its predecessors; hence the great effort to achieve that accuracy back in the 18th century.

The fact is, their time has gone. It's called progress. Of course you can still use a sextant if you want, but why a sextant? Why not an octant or a backstaff? Lots of fun, the backstaff. What's a sextant got that the backstaff hasn't? Why the bias?

See supra, precision AND reliability. Bias? Reliabilty maybe?

Incidentally, have you tried to use a sextant at night? In the fog? In cloudy weather? In snow? In a storm at sea? GPS can give you a position fix (and much more) in an instant under all these conditions. With the push of a button it made the sextant obsolete.

All of which adds up to zilch, zip, and nada if the the batteries go dead, the she ships electrical system takes a vacation, the government for security reasons decides to turn the satellites off...
And by the by redundancy of units does not solve the problem in all cases.

Well, all right, I'll admit there are some of us who actually think taking a sight with a sextant is fun. We kid ourselves it connects us directly with long generations of seafarers, and makes us better sailors. Sometimes, when an easy noon sight confirms our latitude on the coast it may indeed actually be useful. But we're really just playing at being Luddites and pretending we're more knowledgable than other skippers, and therefore more desirable to the hot chicks in the yacht club bar.

An attitude of flippancy not really admirable considering the seriousness of extracting your location at sea, especially with family and crew relying on your ability to provide safe passage. By the way did you see the two(in the last couple of days) articles where people obeyed precisely their infallible onboard navigators while driving? When told to make a left tun now by the charming Sexy silicon, he did so...and entered the front of a building...the street intersection was 30 or so yards ahead.

After one race across the Atlantic, I was invited into the cockpit of the big Boeing bringing me back home, and lo, there was a dedicated navigator taking sextant sights in a special little bubble dome. The year was 1971. How many dedicated aircraft navigators do you suppose there are these days; and how many use sextants?

Cheers,

John V.

Ahhh, but is a boat in constant contact with, and under surveillance by various civilian and military agencies as are commercial aircraft? So does your example apply to General Aviation as well? Doesn't matter really, as planes particularly private aviation are almost exclusively flown over land, and if you survive the landing, you'll probably survive while the plane remains a loss. Can you tell us that the same applies to a boat? No, I thought not. To compare aviation with sea is invalid.

Lastly, I believe that under long established maritime rules, laws, practice etc. it is the captains responsibility to have certain skills that will prove essential in case of an emergency, celestial navigation is still on the masters test.

But wait, I forsee the ..but what about Loran, Radio Direction finding? What about them? Merely upgrades of the electronics. Which brings up the fundamental and glaring reason for maintaining at least a rudimentary knowledge of how to use a sextant...it is NOT part of the electronics! It is a parallel system, another entirely seperate system that provides backup and redundancy for navigation. Ar eyou against backups. Are you arguing total reliance on single systems...especially the latest and greatest in the Seagoing Sharper Image catalog?

Look John, I and most know what I have alluded to in the above does not really apply to you, but off-hand, flippant, not well thought out comments on serious things such as this can be made by the likes of me without damge; however, you as a 'public expert' by dint of your books can kill people by sheer accident...think about it.

[Al Levesque]

Did I read somewhere that the Navy discontinued the sextant? What would Capt Bligh have done? I recall that I had gotten quite repeatable with my practice sextant but I never mastered math without errors unless I used one of those newfangled calculators. Hey, give or take five miles, one ledge is as good as the next.

[Duncan Maio]

We daysail and harbor-hop pretty much exclusively, and in areas that we know well and that are well marked, so at this point in my sailing career I could realistically go all season without any nav aids (except the course book on race nights).

We always have paper charts in the cockpit, and if there is a destination in mind, the course is marked on the chart slicker with a china marker. For speed and postion fixes (in addition to the compass), we use a hand-held GPS that can run off of either the house batteries or its own AA supply. We also use a chart plotter that can be mounted in the companionway or down below using a clamp-on bracket, and is tied into the VHF's DSC system so that the radio will send out a position fix with a distress call, if we ever need one. I didn't spring for the technology that would have put a caller's location on the plotter's screen, and sometimes wish I had.

In addition, my new cell phone has a java applet that runs a nifty little GPS reciever right on the phone display, as an additional backup. The phone also has speed dials for a few marinas, harbormasters, etc.

I never learned to use a sextant, and don't own one, but it's on the list if we ever do more extended cruising or if the kids want to learn when they get older (or if they want to cruise more, or build their own boat). For the territory in which we sail, I figure multiple machines with alternate power sources, plus the paper, are more than adequate backup.

So here's the question for the board: assuming I want to sail more and further, how long a journey warrants learning to take sights with a sextant?

[Joe CD MS 300]

Duncon,

My question similar to yours. What level of precision can you expect from a sextant? 1000 ft? a mile? 5 miles? Is that in ideal conditions? I would think that it's usefulness might drop to zero in bad conditions. A sextant might be a nice backup if you are crossing oceans but for most of the coastal cruising and harbor hopping that I and a lot of us do I would think that it is more or less useless. I'm voting with John.

Joe

[Steve Laume]

I read some where where a well respected captain was being questioned about not carrying a sextant aboard. He had back ups to back ups for GPS units. His answer to the question was to question the interviewer, as to weather he kept a horse and buggy in his garage in case something happened to his car. The times they are a changin, Steve.

[Neil Gordon]

What level of precision can you expect from a sextant? 1000 ft? a mile? 5 miles?

I'll respond to a number of comments made in a number of messages.

The astrolabe, cross staff, backstaff, octant, sextant, etc., all served the same purpose, which was to measure the angle between this and that. The devices evolved as technology allowed for more accuracy and ease of use. (The backstaff was a major improvement over the cross staff, as the later required the navigator to stare directly into the sun, commonly burning a hole through the back of his eye after a while.) Once the angle was measured, you relied on tables and calculations to determine your position.

Electronic navigation changes the paradigm from more accurate measurement of angles to whiz bang gagetry. So while the sextant is an improvement over the backstaff, the comparison of GPS to sextant isn't as easy. If your batteries go dead, a backstaff would do you better than the gizmo.

There's also a fundemental shift in navigation which is now about knowing where you are. In a lot of ways, traditional methods are about knowing where you're not. So we all tend to sail closer to rocks and are more likely to take the narrow passage between unmarked shoals now even when prudent seamanship would have us further off.

As to where you would use a sextant, it's not now nor has it ever been a tool for coastal cruising when piloting is the preferred navigation method. (I'm speaking only of traditional sextant use, not measuring the angle to the top of the lighthouse or the angle between land objects, etc. A sextant is good for piloting, too, if you use it that way.)

A sextant in the hands of a skilled navigator is easily capable of determining position within three NM or so. That's well within the visible horizon and sufficient for making landfall anywhere on the planet. It won't take you through a 50 ft narrow channel dotted with rocks, at night.

How long a passage justifies sextant use? If I'm offshore enough to take a noon site with a clear horizon to the south, that's long enough for me.

I don't sail because it's the fastest way to get there. Navigation is a simple pleasure that adds to the total experience. I use my GPS, too, and more often than not, it's a primary navigation tool. But sometimes I like leaving it turned off because getting from here to there by more traditional means is satisfying. It's much the same as plotting and planning tides and currents, plotting and planning routes and courses from here to there, sailing off the mooring, going this way and that way running, reaching and beating, etc., etc., including at times when turning on the motor might get me there more quickly and in a straighter line.

[Didereaux]

As Neil pointed out, it is the type of sailing which dictates methods and equipment.

Daysailing within site of your backyard requires little if any.

Daysailing beyond ones marina or the racing buoys at minimum require a compass and a chart.

Daysailing out in larger lakes and bays always require charts.

Coastal sailing add in a sextant for triangulation horizontal and vertical. Charts are required for this. ALso it is very useful to check closing angles from ships.

Off-shore is the celestial navigation use of the sextant.

The problems in discussing the necessity of a sextant always winds up the same way...some daysailors(ya gotta love some of the clowns) simply cannot get it through their skulls how to differentiate between off-shore and marina sailing and so pooh-pooh the sextant and drool all over their chart-plotters and GPS's (a habit by the way that carries certain risk to the units heh)

Point is that a sextant is still not just prudent to have along on an extended off-shore or coastal, but has very handy and sometimes needed uses for coastal navigation as well. When used to pre-plot courses around charted objects with checks by angle from other objects their precision is quite high, whereas it has been pointed out quite rightly that celestial shots are usually 3-5 miles accuracy well within line of site, which is absolutely all you need approaching or making landfall or checking positioning at sea.

I would add that only a very foolish person would rely on chart plotters when trying to navigate any of the area within a 100mile radius of last years hurricanes, NO chart and certainly NO plotter or GPS can tell you accurately where some of the things, such as buoys presently are. Very little in the way of refurbishing buoys has been done by the CG (lack of funds)...you are on your own.

Just remember to match the equipment and methods to the conditions! ...and then cross your fingers and toes.