What is a good steering compass?

[tat]

What would be a good steering compass?

I bought one on the internet for £7.24, a ball type. I had a good look at it and, well, it stuck when it had just a bit of tilt, and, whilst I understood the north being south, etc, if you will, which is ok, the graduations were strange, and difficult to read. It made no sense to me at all. I want 0 degrees to 360 degrees, clear, and that it works well.

The one I bought had, if I remember, 60 divisions between, say, east and south. I would have thought it would be 90 divisions, or at least something divisible with 90.

[GordMay]

The traditional mariner’s compass consists of 32 points, corresponding to the cardinal and intercardinal directions.
Each point is 11.25 (360 ÷ 32) degrees.

On the other hand, to scientists, engineers, and mathematicians it is usual to measure angles in radians.
The size of a radian is determined by the requirement that there are 2pi radians in a circle. Thus 2pi radians equals 360 degrees.
A circle has 360 degrees or 2pi radians — going all the way around is 2 * pi * r / r. So a radian is about 360 /(2 * pi) or 57.3 degrees.

[PangurBan]

Originally Posted by GordMay

The traditional mariner’s compass consists of 32 points, corresponding to the cardinal and intercardinal directions.

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[PangurBan]

I think the old mariner's compass had 11 and a quarter degrees per point. 11.25 x 32 = 360.


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[jreiter190]

I have a Saturn bulkhead compass in the cockpit , graduated in five degree increments and a beautiful old Kelvin White Constellation that I moved from the cockpit to the cabin, also with five degree increments. On a small boat you don't need a compass graduated in one degree incements because you can't steer that small. I was underway replenishment helmsman on a LST in the Navy. While alongside the supply ship, I was allowed 1/2 degree either side of the course for up to 45 minutes until the last line was free. The Conning Officer would give left 20 degrees and I would step away from the wheel and someone would hand me a cup of coffee and a lit cigarette. I would be trembling from the stress and stand by for the next pass in fifeteen or twenty minutes. We would sometimes make four runs. THAT'S when you need a compass graduated in single degrees.

[ArmyDaveNY]

Originally Posted by jreiter190

I have a Saturn bulkhead compass in the cockpit , graduated in five degree increments and a beautiful old Kelvin White Constellation that I moved from the cockpit to the cabin, also with five degree increments. On a small boat you don't need a compass graduated in one degree incements because you can't steer that small. I was underway replenishment helmsman on a LST in the Navy. While alongside the supply ship, I was allowed 1/2 degree either side of the course for up to 45 minutes until the last line was free. The Conning Officer would give left 20 degrees and I would step away from the wheel and someone would hand me a cup of coffee and a lit cigarette. I would be trembling from the stress and stand by for the next pass in fifeteen or twenty minutes. We would sometimes make four runs. THAT'S when you need a compass graduated in single degrees.

It's a good thing you didn't have to use mils...6400 mils in a circle! We had those in the tanks although we didn't use them to maneuver, just to align the turret with preselect target reference points.

[ArmyDaveNY]

"I bought one on the internet for £7.24"


Buy quality, cry once. Buy cheap, cry often! It's not always true but is true more often than not.

[hamburking]

This is the 21st century. I read the course off the chart plotter or autohelm display. For backup, a plastimo handbearing compass and an old garmin etrex.

[jreiter190]

Originally Posted by hamburking

This is the 21st century. I read the course off the chart plotter or autohelm display. For backup, a plastimo handbearing compass and an old garmin etrex.

And when your chart plotter takes a dump, it's the 19th century again

[msrcal36]

The best I had was 6" Danforth Constellation. Big numbers on the card very easy to read. Unfortunately it's no longer made. The last one I bought was used (eBay).

[tat]

Thank you all for your replies. I knew not to expect much with £7.24, but you have to start somewhere, so it was a cheap inroad.

I have never heard of cardinal and intercardinal directions, so I will look into that. I guessed there would be a good reason why it was divided up in that strange way. Thanks for that info. I will find out so that it makes sense to me before I buy a good compass.

Steering a large ship within half a degree, needing that level of concentration. I can empathise with you a bit. I often travel through a tunnel, a mile plus, and the arch is such that my canopy would scrape the walls first, so I have to really concentrate for 15 mins. It is difficult when concentrating constantly because it keeps trying to put you in a trans, like the old Dr Who opening credits, and you have to keep shaking yourself out of it. So I can well imagine how it must have been for you......a coffee and lit cigarette. Ha, ha.

And then 6400 mills in a circle. That really is fine work. I bet you could hardly take a breath. Ha, ha.

[Dave22q]

increments smaller than 5 degrees are difficult to read unless the compass is extremely large. A good steering compass depends on the size of your boat and how you use her. I never worry about course deviations of a degree or two as wave and wind action makes holding course an averaging process. About the only time I want precision is in navigation when sighting a mark but that is using a different instrument entirely (hand held sighting compass).

[Cadence]

An old Kelvin White, Constellation is marked both ways with degrees being to the outside of the card.

[ArmyDaveNY]

Originally Posted by jreiter190

And when your chart plotter takes a dump, it's the 19th century again

+1 Chart plotters are great when they work. Remember Murphy's law; if it can go wrong it will. Team Vestas Wind had chart plotters too! Also, are you really going to hold a hand held compass for hours trying to navigate?

[alansmith]

Navigation is one of the most fascinating subjects there is. You should also educate yourself about magnetic deviation in your region.

For example there is True North and Magnetic North. They are not the same. Depending on where you live you have to know what that deviation is for compass and map work. Read up or take a course it is really cool stuff. Nowadays with gps it is all done for u. like Johnnie Miller, a highly decorated golfer and golf commentator said while Tiger Woods was at the height of his success..."just because he is the best putter in the world doesn't mean he will always be able to drop them." He caught a lot of flak for that comment. So, how do I tie that into this subject... Just because we have gps now doesn't mean we will always have it. China has already shown the international communities that it can destroy satellites in orbit. Do u have any idea how much I our military infrastructure depends on satellite gps info? If a war broke out do u think military commanders would leave that card untouched? I think map and compass work is one of the coolest mind stimulations there is in a boat. Don't miss the opportunity to improve your skills without gps... Use it as your backup plan. Just my way of thinking.