Is a Compass your Primary Navigation Instrument or Back Up?

[cwyckham]

Originally Posted by Dale Hedtke

Please explain how a 2 second lag is a "lie." Define lie.

Virtually no information is ever current, no instrument 100% accurate.

That said, why would you care if your information is 2 seconds old?

On our boat we don't use the magnetic ship's compass often, but I would not want to proceed without it for reasons given above.

If you're navigating, a 2 second delay is irrelevant. If you're steering, a 2 second delay is forever. You'll go in circles.

[DefinitelyMe]

Primary instrument is clouds, cloud movement and stars, cross-checked occasionally against the compass (unless i'm going northish on a clear night, in which case everything but the north star becomes redundant). I don't have any electronic instruments and have no intention of fitting them. Too expensive and unnecessary in my opinion. I also find it's easy to get transfixed on the LCD displays, and i end up not looking around me as much.

[Jammer Six]

Originally Posted by Pelagic

I think we ALL agree that a compass is our primary “Piloting” tool… i.e. keeps us going in a straight line!

No, we don't.

You don't appear to have read all the posts.

[MarkJ]

Originally Posted by Pelagic

I think we ALL agree that a compass is our primary “Piloting” tool… i.e. keeps us going in a straight line!

I agree with Jammer 6.

Its definitely not my primary piloting tool.

[psneeld]

Originally Posted by cwyckham

If you're navigating, a 2 second delay is irrelevant. If you're steering, a 2 second delay is forever. You'll go in circles.

Not quite sure about your boat...but every one I've steered that runs under 10 knots, 2 second steering would be over correcting.

If it's that rough on a small boat to steer that much...usually the compass is all over the place anyhow.

Not sure if I know anyone that uses a compass for anything but a glance these days.

We have moved into the 21st century.

[Jim Cate]

I'm finding this hilarious!

In this corner, wearing white trunks, is the no electronics, compass needed to get anywhere, sextant for entering the marina on a lake in Az champion.

In the other corner,wearing black trunks, is the electronic believer, hasn't even seen his compass in years, follows his course on a plotter of some sort champion who somehow has managed to circumnavigate safely.

Gentlemen, touch gloves and come out fighting when the bell rings!

Ohh... but if it should be foggy, use your floating card compass to find the center of the ring and each other. If you rely upon an electronic device, you might hit the referee!

Cheers,

Jim

[sailorboy1]

I'm a little confused (of course), but when I'm in fog I pretty much am only using my chartplotter. I don't really care what direction on the compass I'm going, all I care is what is around me and am I heading to it and is it something hard.

My compass is NOT my primary anything.

[mpatter894]

The answer to the question is yes to both ,its your primary if that's all you have and its secondary if you are using any other means to determine your heading other than terrestrial navigation using relative bearings. Never forget who owns the GPS satellites, they were developed for the US Navy and Air Force they can turn them off any time they want and use them in encrypted mode , not that it would happen but best to have a magnetic compass if you plan on heading out to sea.

and remember when adding all your new electronics next to your magnetic compass on the binnacle to do a comparison afterward.

USCG Master Mariner any gross tonnage any ocean

[sailorboy1]

maybe I should tell you of the time when I was on submarine duty and our gyro lost power and the result was that we went south when we wanted to go north

of course that was after surfacing and taking a star mark, for you sextant type people

[mpatter894]

here is what I find funny about most of the people on this forum couldn't navigate their way through a bathroom if it was not for electronics. I am all for them but in the wrong hands they can be dangerous, out allows to many idiots out on the water that have no right to be there more than 80% of the people that have boats couldn't pass a rules of the road exam so they go and buy a boat anyway load it with electronic charts and auto pilots push the buttons and go god help them if they get into a close quarter situation where they might have to move off the line of the chart plotter. I bet if I asked which way a compass spun when you turned to starboard or port 80% would get that wrong also because the compass doesn't move the boat does.


Unlimited tonnage USCG Master

[sailorboy1]

should be careful with throwing around general insults (since you just said 80% of us don't know much of anything), I can put together a lot of examples of master mariners going aground

[IslandHopper]

Originally Posted by Pelagic

I would go one step further and say that my training is my primary navigational instrument.

Exactly......my primary navigational instrument is between my ears, my Steering compass, HH Bearing Compass, paper charts, Sextants, Radars, Sounders, Chartplotters, AIS etc. etc. are all tools at my disposal. It's my training and experience in using these tools that tell me which I should be using at the time and how to seamlessly move from one to another should one or more fail or become unreliable.....

[cwyckham]

Originally Posted by psneeld

Not quite sure about your boat...but every one I've steered that runs under 10 knots, 2 second steering would be over correcting.

If it's that rough on a small boat to steer that much...usually the compass is all over the place anyhow.

Not sure if I know anyone that uses a compass for anything but a glance these days.

We have moved into the 21st century.

To illustrate: You are approaching a bend and you want to steer 90 degrees to port. You're motoring and going 5 knots. You put in a reasonable amount of rudder and start to turn. It will take you about 10 seconds to make the turn. Except your electronic compass is 2 seconds behind. So it tells you you've turned 90 degrees when you've actually turned 100. You straighten out and a couple seconds later you found you've over-steered. So you turn back the other way. And over-steer again for the same reason. Etc. etc.

The key is to match your rate of turn to the delay in your compass. I find my GPS has a 5-10 second delay because it's actually calculating based on COG and I'll literally drive in circles. Two seconds wouldn't be terrible if you just drive like a little old lady and make sure you start straightening out early, etc.

[cwyckham]

Originally Posted by sailorboy1

I'm a little confused (of course), but when I'm in fog I pretty much am only using my chartplotter. I don't really care what direction on the compass I'm going, all I care is what is around me and am I heading to it and is it something hard.

My compass is NOT my primary anything.

I totally agree. In the situation I described, I was 100% using the chart plotter for navigation (as well as my ears and occasional glimpses of rocks). However, I couldn't use it for steering because it lagged way, way too much. It was too coarse and too slow for that. So I had to use the compass to make sure I was going in a straight line (didn't matter which direction), then use the chart plotter to make sure that direction wasn't going to get me up on the rocks. If I needed to ease to port, I'd turn port 10 degrees using the compass, let it settle for 5-10 seconds on that heading, then check the chart plotter to make sure the little arrow no longer went over the beige bit.

I literally did a 180 in the middle of the bay when I tried to do it based on chart plotter alone, due to the lag.

[psneeld]

Originally Posted by cwyckham

To illustrate: You are approaching a bend and you want to steer 90 degrees to port. You're motoring and going 5 knots. You put in a reasonable amount of rudder and start to turn. It will take you about 10 seconds to make the turn. Except your electronic compass is 2 seconds behind. So it tells you you've turned 90 degrees when you've actually turned 100. You straighten out and a couple seconds later you found you've over-steered. So you turn back the other way. And over-steer again for the same reason. Etc. etc.

The key is to match your rate of turn to the delay in your compass. I find my GPS has a 5-10 second delay because it's actually calculating based on COG and I'll literally drive in circles. Two seconds wouldn't be terrible if you just drive like a little old lady and make sure you start straightening out early, etc.

OK... I see your point as small as it may be...I'm not sayig a compass is useless I'm just saying it is at the bottom of my nav usefulness in my 21st century navigation spread.

Yes I navigated both in boats and helos long before any even had LORAN...yes I used to know Celestial, yes I run commercial boats for a living...yes I hardly think of ever using a compass exceot as an after thought because I have adapted to a quicker, more accurate, more versatile way of navigating.

If you don't think so...ask an airline pilot when was the last plane he flew with a celestial bubble in the top....I've been in one and couldn't even imagine...so I don't bother today.

If I were crossing oceans...yes I would make sure my compass was swung as good as I could get it and I would brush up on a few celestial tricks ...but please don't insult my professional navigation skills with a bunch of old school stuff that I still can mostly do in my head but really don't have to anymore.