1. Compass card with triangle that points to magnetic north
2. Rotating bezel for setting direction to target
3. Sighting line and window for reading precise bearing
4. Orienting indicators for maintaining direction of travel
ORIENTATION AT THE DIVE SITE
To better understand your surroundings, you should use your compass
to orientate yourself already on the surface. Underwater navigation is
demanding, so using the compass already at the shore or on the boat
helps you better understand your movement underwater.
Before diving, check the shoreline or boat position relative to magnetic
north and your planned dive route. This helps you underwater to
navigate towards the ascent place where you want to end your dive.
If you are using, a map you should first turn your map in the right
direction. This ensures the geographic features around you are in the
same general direction as you see them on the map.
1. Hold your compass level and look at the triangle to see where
north is.
2. Turn the map so that the northern upper edge is pointing north.
1
The meridian lines on a map indicate the direction toward true north
while your compass needle indicates the direction toward magnetic
north. The angle between these two directions is called magnetic
declination.
You should check the magnetic declination for the dive site from
a trusted source, such as a recent map or the NOAA website. If
the magnetic declination is more than a few degrees, you must
compensate for it when navigating with a compass.
SIGHT A BEARING
A bearing is the angle between direction to north and the direction
to a target. This can be used in communicating directions with others
or when finding your location.
1. Hold the compass level with the sighting window facing you.
2. Align the target with the bearing line.
3. Read the bearing from the sighting window.
NOTE: Compensate for declination.
At the dive site, you should establish your general orientation by
sighting bearings of your underwater navigation aids, such as a
shoreline or reef. Memorize or make note of these bearings to use
while diving.
MAINTAINING DIRECTION OF TRAVEL
With practice, you can maintain your direction of swimming over
long distances using your Suunto dive compass.
1. Find a visible target in the direction you want to travel.
2. Hold the compass level in front of you with sighting window
facing you.
3. Turn the bezel until the orienting indicators are aligned with the
triangle.
Swim towards target and check your direction when the target is not
visible by holding the compass as in step 2 above. If the orienting
indicators and triangle are not aligned, turn yourself until they are
aligned and continue travelling in the corrected direction.
2
Do not use the compass before you come to rest and can align the
compass horizontally with the aid of a flat bottom, a glimpse of the
surface, your own bubbles going up, or the pull of gravity. In poor
light or very murky water, swing the compass slowly from right to
left to ensure the compass card moves freely before checking your
bearing.
NAVIGATION AIDS UNDER WATER
The dip and stratification of rocks on the shore can often be followed
over large areas under water. Sand ripples may also form long lines
parallel to the shore that can be used for maintaining your direction
of travel.
The direction of currents should be noted by their effect on algae
or drifting particles. Use the compass to check the bearing of the
current.
Swimming in a straight line along the bottom is greatly facilitated if
you can line up three distinctive targets in your line of vision. As you
reach the first target, line up a new one farther away, so that you
again have three points determining your course. This way you can
counteract the effect of a side current.
In clear water, the compass can be used to swim in a search pattern
over a fairly large area. Count your swim kick pairs (each left or each
right kick), swimming on one of the cardinal directions (North, South,
East, West).
Count up to 100 kick pairs (roughly 100 meters), turn 90 degrees,
swim a few kicks, then turn 90 degrees further, and again swim
the same number of kick pairs. Continue the pattern for as long as
necessary.
The side displacement between each turn in a search pattern depends
on visibility. Keep the disatnce between each turn shorter than
theoretically possible.
3
CARE
Use only fresh water and mild soap for cleaning. Clean your compass
after each dive.
· Operating/storage temperature: -30° C - +60° C / -22° F - +140° F