Kirby 77 Scuba Diving Equipment User Manual


 
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© Copyright 1970-2008 Kirby Morgan Dive Systems, Inc. All rights reserved. Document #080626002
Kirby Morgan 77
Neck Dam components.
dam opening so that the two “edges” of the neck
dam are parallel. The neck dam must be under slight
tension but must not be stretched beyond its normal
length. Trim the neck dam with the largest, sharpest
scissors available, in order to make as few cuts as
possible. There must be no jagged edges on the neck
dam or it may tear.
Trim only 1/4 inch off the neck dam at a time. When
you are done, the neck dam must be just tight enough
KMDSI must have your current address to
ensure that you receive all safety notices
and other important information concern-
ing the helmet. Please notify KMDSI of
any change of address.
WARNING
3.4 Initial Adjustments to
Your Helmet
Before using the helmet for the first time, it must be
checked and adjusted for proper fit. There are several
adjustments that must be made to provide a more
comfortable fit when wearing the helmet.
3.4.1 Head Cushion
The fit of the helmet is primarily determined by the
layers of open cell foam that fill the head cushion
bag.
The center top/rear foam is very dense to reduce
compression and spring-back. This reduces the ten-
dency of the helmet to ride up when underwater. Do
not replace this rigid foam with a soft foam. A softer
foam is used on the sides and around the bottom of
the head cushion.
The diver’s head can be moved forward into the oral
nasal mask by adding layers of additional foam at the
rear of the head cushion. Do not add to much foam to
the rear of the head cushion, as this may position the
diver’s chin too far into the oral/nasal mask and create
an uncomfortable fit. The diver’s head can be moved
up or down in the helmet by decreasing or increasing
the foam pads at the top of the head cushion.
Usually, a diver with a small head will use all the foam
that comes with a new hat. A diver with a larger head
will need to remove a layer of foam in the center top
and back of the head cushion. The foam may be cut
with scissors to provide a better fit, or more foam can
be added to give a tighter fit.
The chin cushion can also be adjusted if necessary.
3.4.2 Trimming the Neck Dam
If your helmet is new, or any time you replace the
neck dam, it must be adjusted to fit you. New neck
dams are cone shaped and will probably be too tight
if not properly trimmed.
The neck dam must be trimmed to fit your neck. To
trim the neck dam, have your tender hold the neck
Never dive with a neck dam that is too
tight. A neck dam that is too tight could
cause the diver to pass out due to pres-
sure on the carotid artery in the neck.
This could lead to severe personal injury
or death.
WARNING
The head cushion should be adjusted for best fit.
O-ring
Split
Ring
Neck
dam
Stepped
Ring
Pull
Strap
Screw