PLASTIMO
Compasses
Plastimo owes it's position as market leader not
only to their extensive range of yacht compasses, but
also to the continuous R&D effort needed to offer
such a top quality product.
Selecting the best compass for your boat is
extremely important, as the compass will be the the
helmsman's navigation mate for many years. Your selection
should be made taking into consideration
... Your type of boat: dinghy, cruising boats,
racing boats, power boats... Features may include a
removable compass on a fixed bracket, a fully gimballed
unit, a tactical card, or a spring loaded suspension (for
power boats).
... Your type of navigation: day sailing,
cruising, long shore navigation... You may select small
or larger compasses with or without lighting, with or
without compensation, with the right balanced card for
the geographical area where you are going to
sail.
... The location of the compass on the boat:
bulkhead mounted compasses, flush mounted compasses on
the deck or on the dash board, mounted on a steering
pedestal, on a mast bracket... you will choose a compass
which is easily readable. Often located at the heart of
your boat, your compass should ideally match and enhance
the character of your boat ; you will therefore pay
particular attention to its design and colour.
Some helpful hints
How to establish a deviation curve with a
handbearing compass
Plastimo Compasses suggests an extremely quick
and easy method which consists of comparing the
information given by the steering compass in different
directions with those of the handbearing compass which
would be used in an area free of magnetic
disturbance.
Finding the ideal location on board
Firstly, a seamark should be picked out. This
will serve as the point of reference. This point should
be at least 3 miles from the boat and the sea should be
calm. Locate an area on board that in principle is not
subject to magnetic disturbance. The rear of the boat is
usually a convenient location. Then, whilst pinpointing
the seamark with the handbearing compass, turn the boat
slowly round in a circle about 4 to 5 times the length of
the boat. If the bearings remain constant, this means
that the location you have chosen is free from magnetic
disturbance If this is not the case, find another
location on the boat.
Checking the accuracy of your ship's steering
compass
Turn the boat round in different directions and
compare the course readings of the steering compass with
the handbearing compass which should be positioned along
the longitudinal axis of the boat. Any difference is due
only to the deviation of the steering compass.
Establishing the deviation curve
In the event of deviation, turn the boat in
various directions (N, 22º, 45º, 68º, E, etc.) and note
the differences. Then trace out the deviation curve of
the steering compass. If the steering compass has a
higher course than the handbearing compass this means
that the deviation is west and vice versa.
Compensation of your ship's steering
compass
If the deviation is more than 10º, your
ship's steering compass must be checked for compensation. If
this is the case, refer to the steering compass instruction
manual.
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