8
your line of vision. As you reach the rst one, 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.
Using the compass under water
- Usually, a compass must be held precisely in a
horizontal position, otherwise the magnetic needle will
stick. However, in the SK-7 the allowed inclination is
approximately ±30 degrees.
- Do not attempt to use the compass before you come
to rest and can align the compass horizontally with the
aid of a at bottom, a glimpse of the surface, your own
bubbles going up, or the pull of gravity. When doubtful,
as in darkness or very murky water, turn the compass
slowly right and left, checking that the North needle
swings freely, before trusting your bearing.
- Swimming along the bottom, make use of xed points.
Keep still until the needle settles between the slit marks
(your predetermined bearing), choose a distinctive object
near the edge of vision in that direction, swim toward it,
and repeat the operation on reaching it.
- Commonly, the diver wants to follow a predetermined
bearing under water, trying to reach a wreck, a rock etc.
When submerging after obtaining the bearing on the sur-
face, he must be careful not to accidentally disturb the
direction ring, and to be on the safe side, the compass
bearing should always be memorized.