Tuesday, 13 October 2015

Checking the compass deviation using the Sun

Our Plastimo steering compas has a pointer to cast a shadow to check for compass deviation.

It is 11:35 UTC  on 10/10/2015 and we are at around 54 deg 10 N 1 deg 10 W so the LHA of the sun is 178 deg.  Variation is 3 deg W, so the compass bearing of the sun should be 181 deg and the shadow 001 deg. We can't read the compass to that accuracy but it looks about bang on.  It is a pity Plastimo did not make a longer pointer.  Repeating the exercise turning the boat around we can swing the compass and make a deviation card. Not however while the First Mate is passing a cup of soup up the companionway.

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