Poseidon SE7EN User Manual
Appendix 3 Page 114
Breathing underwater
Counterlung placement
When properly adjusted, the Poseidon SE7EN should rest easily on the diver’s back. It should
not feel awkward or loose, but rather it should be reasonably snug and comfortable. Specific
strap adjustments will depend on what style of harness is used, but each counterlung comes
with a set of three straps that can be looped around the harness shoulder straps, securing
both counterlungs firmly to the diver’s upper chest and shoulders. When properly positioned,
both counterlungs should curve over the tops of the shoulders, such that the top ends are in
line with the diver’s back. They should hug the diver’s body closely, and not float up or shift
position as the diver swims in different orientations.
Counterlung strap adjustments
Besides the three large straps for attachment to the harness, each counterlung has several
additional straps used to adjust positioning. At the top of each counterlung is a single adjust-
able strap that curves behind the diver’s back and attaches to the corresponding cylinder
strap. This counterlung strap is used to adjust the positioning of the top of each counterlung.
At the bottom of each counterlung are two more adjustable straps. The longer of these angles
straight down for attachment to a crotchstrap or a waist strap, and is used to keep the bottom
of the counterlung securely down. The shorter strap angles laterally and attaches to the cor-
responding strap on the other counterlung. These two keep the counterlungs held together.
It is well worth the time spent in shallow water making adjustments to these various straps until
the counterlungs fit comfortably and closely to the upper chest and shoulders. The better the
counterlung adjustment, the easier the breathing will be when underwater.
