Quote:
Originally Posted by Savanna
Hi Fellow Lagoon Lovers,
I wonder if any of you have experienced the same issue as myself with the steering compass. The magnetic compass reading on our L400 always seemed to me to be incorrect, and I have finally purchased a hand bearing compass to check it out. The result of my checking is that there is something near the steering compass which pulls the card almost 25 degrees to port. The same happens to my hand held compass as I bring it closer to the position of the steering compass.
Has anyone experienced the same issue? and if so, what (if anything) were you able to do about it?
Twenty-five degrees is a bit much to be showing on a deviation card.
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Ok, Savanna, a couple of things to check.
Firstly, is your compass made for the southern hemisphere? If, it is original fitment
Plastimo Offshore 95, you can check this by going to the
Plastimo website and checking the region code. For NZ, it should be 0062-10, or similiar.
Our vessel came with the northern hemisphere model, which could not be "swung" accurately. You can upgrade to a model that is adjustable for worldwide use, but these are quite expensive.
Secondly, has your compass been "swung" ?
Once, you have a suitable compass, read the manual regarding how to "swing" or adjust using the built in adjustment magnets. These will go a long way towards counteracting the effects of magnetic
interference. You should be able to adjust a Plastimo 95 to within 5 degrees accuracy. Make sure you turn on all
electronics when you swing the compass, as electronics on or off can make a significant difference. Downunder is correct in saying that designing helms for
remote and accurate compass mounting is not a high priority.
Once swung correctly your compass will probably be adequate for general coastal
navigation use. Especially if you are like most and tend not to use it! If you wish to use it for "real"
navigation, go the next step and prepare a "deviation card", a table of corrections for each 10 degree of the compass headings. eg. " at compass heading 90° deviate plus 2°" etc.
This is easy to prepare using a trusted
GPS to compare headings and a bit of time on a calm day.