Let's talk compasses

Grumpy":vdx6d609 said:
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Try putting you cell phone within 1 ft of the compass and see what happens..
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Merv
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A cell phone can deviate a compass a good 5 degrees in my experience.

I prioritize a good night lit compass for any vessel I use. I've always had good experience with Ritchie products (company is based here in MA). Only their largest compass (Globe Master) comes with a 2 degree marking option on the card. All other products come with the 5 degree card markings. I would love to have 2 degree increments but the largest compass would occupy more space than I will prioritize.

Thanks for the suggestions.
 
When outfitting "Sea Shift", Les installed a compass that can be "quick released" from its' base mount and then it becomes a hand held compass. This allows me to carry it out into the cockpit, where I can be certain that I am clear of any thing of interference that would cause compass deviation.

(Hence, no deviation, unless I hold it close to the cell phone or numerous pagers and knives that I have hanging off my belt..........of course the steel plate in my head doesn't help much either... :roll: )
 
Dave, You want to compensate the compass/draw deviation tables with the compass in its usual position on the dash. Even in the cockpit, there can be magnetic influences from metal objects--plus there is the problem of how to line the compass up fore and aft accurately. You will be steering with the compass from the location at the helm.

As Dan rightfully suggests a hand bearing compass should be part of the gear aboard. We use a Vion puck type. It has a split prism and reads to a degree--both from above and when sighting on an object. We also use the compass in the 7 x 50 binoculars as a head bearing compass.
 
I have more compasses than a person really needs, but like the American Express Card man on TV, I never leave home without one.

I have a Ritchie Compass that was on my boat when I purchased it. For it’s size (I am guessing it has a 3 or 3 ¼ inch dial) it is somewhat inaccurate with 5 degree markings but adequate for a boat. It’s probably accurate to within 1½ degrees.

The two hand held sighting compasses I have is a Suunto with a 2¼ dial and capable of a 1 degree accuracy. The other is a Steigung with a 2½ inch dial capable of a ½ degree accuracy. Neither one would be much more accurate than the Ritchie compass on my boat. You need a stable platform to read with that kind of accuracy and a boat is not, except in dead calm water.
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Dave dlt.gif
 
oldgrowth":2dcftjpy said:
I have more compasses than a person really needs, but like the American Express Card man on TV, I never leave home without one.

I have a Ritchie Compass that was on my boat when I purchased it. For it’s size (I am guessing it has a 3 or 3 ¼ inch dial) it is somewhat inaccurate with 5 degree markings but adequate for a boat. It’s probably accurate to within 1½ degrees.

The two hand held sighting compasses I have is a Suunto with a 2¼ dial and capable of a 1 degree accuracy. The other is a Steigung with a 2½ inch dial capable of a ½ degree accuracy. Neither one would be much more accurate than the Ritchie compass on my boat. You need a stable platform to read with that kind of accuracy and a boat is not, except in dead calm water.
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Dave dlt.gif
Click to expand...

This reminds me....I mostly dive from my boat and this means I will have at least 3 other compasses in the dive gear. Ha ha - I think I will be set!

Thanks for the replies. I will go with the Ritchie Voyager as my primary vessel compass.
 
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