Chapter 4- Night and Limited Visibility Diving
Night and Limited Visibility Diving
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ascent line or following the contour of the bottom to and
from shore is suggested. Both techniques help you avoid
being in mid-water with no reference.
OVERVIEW OF A TYPICAL
INTRODUCTORY DIVE
Your night dive may be preceded by a daytime dive
at the site. You might engage in a social activity while
waiting for darkness or you may reassemble at the
staging area after dark. The objective is to be familiar
with the area. Your instructor will brief you on the particulars
and recap the main points to keep in mind. A
lot of attention will be given to your equipment and your
lights. If you do not own or are not ready to purchase
a good dive light for this dive, you can probably rent/
hire one from you local NAUI affiliated dive center.
Depending on your instructor’s preference, you may need
to use a chemical light or battery powered locator light.
During the actual dive your instructor may choose
to lead all of the dive teams as a group, or you may be
assigned to dive by teams in a specified area. Either way,
your descent will probably use down-line or follow the
contour of the bottom so you will have a continuous
reference. The underwater tour follows your descent,
and time passes quickly as you become engrossed in the
way things appear as your dive light cuts into inky dark.
Your instructor may have you settle to the bottom, remain
motionless, and turn off your lights to see what it is like
without them. Soon you will be able to make things out
and will discover that the glow lights put out quite a bit of
light when they are the only source. Your instructor will
turn on his or her light as a signal for you to turn your
lights back on and resume the dive. Until then you should
remain motionless on the bottom.
Your ascent will also be controlled via the line or
bottom contour. Surface lights will help you recognize
the exit area.
Afterwards, even the discussion of the dive is special
at night. If there is insufficient light to allow you to fill
out your logbook, be sure to complete it at the earliest
opportunity and to have it signed by your buddy and by
your instructor.
A limited visibility introductory dive usually consists
of dive teams following an assigned heading or course
underwater. The use of buddy lines may be introduced.
Your primary goals will be to navigate accurately and to
maintain buddy contact.
Your opportunities to dive can be increased once
you are trained to dive competently at night or in limited
visibility. After discovering what either or both of these
activities is like, you will probably want to develop your
abilities further so you can take advantage of opportunities
that may arise. Ask your instructor about the NAUI
Limited Visibility and Night Diving Specialty course. Now
that you know it is fun to do these activities, why not
have some more fun and gain the training and experience
that will enable you to engage in them safely without
supervision?