Marine Tech Seacraft ENC II, Quick User Manual, Page: 46 / 52

46
LIMITATIONS:
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ENC device should be placed at least 0,2m (7,9”) from any element containing ferromagnetic material (engine,
battery), permanent magnets (engine, vehicle handles, speed sensor) or electrical wires connecting the battery
with the motor. If this rule is violated, compass indications may be incorrect.
- Compass indications may be less stable when ENC tilt exceeds 35° (from vertical position). If you include your
vehicle lean, you should not exceed 35° inclination of ENC device vs vehicle body (see picture above).
-
Log sensor should be placed away from any elements that can disrupt the flow of water. Front of vehicle is
almost always the best choice. Have in mind propeller “sucking” effect, and avoid placing it in the water intake
area.
If you need to place ENC device on some other kind of underwater vehicle, you have to find best mounting points on
your own, using picture above as guidance.
In order to maintain the correct compass accuracy, it is recommended to always calibrate the compass before diving.
Indicated by the compass the direction is calculated from the device measured by the magnetic components of the
Earth measured by the magnetometers. These components change depending on the location, local geological
conditions (eg the presence of ferromagnetic minerals) and are subject to periodic changes. Large ferromagnetic
elements, eg shipwreck, reinforced concrete port quay or steel elements buried in the bottom, also very strongly affect
the work of the compass.
A poorly calibrated compass or its disturbed operation can cause significant errors. In the case of a route with a length
of 1km, 5 degrees of compass error will result in an error in the calculation of the target of almost 88m.
One should also remember about the differences between the magnetic direction indicated by the magnetic compass
and the geographical direction that can be read from the maps. The difference between these courses is called
magnetic declination and depends on the location. The device allows you to set the magnetic declination and offset
this difference.
In order to optimally use the device, it is recommended to familiarize with the theory and principles of navigation in
detail.
The log sensor is a precise electromechanical device and must be protected against mechanical impacts and
contamination. After the dive, it is recommended to gently rinse with fresh water to cleanse any remaining vegetation
or mineral impurities. If it is necessary to make measurements with full precision, it is recommended to calibrate the
log every time.