Hollis Explorer User Manual - −
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Bailout gas volumes should be calculated based on the depth of the dive
and the ascent gas requirements. Cylinders can be positioned on D-ring
attachment points on the harness or optional EXPLORER BCD.
Your Instructor and Training Agency will detail how to calculate for suffi-
cient bailout gas volumes.
COUNTERLUNG VOLUME
The volume of gas in the counterlungs will affect the ‘breathing feel’ of
the unit. Too little gas will make inhaling difficult and too much will make
exhaling difficult. All retreathers have optimal positions in the water where
they have a better or worse breathing feel due the hydrostatic effects of the
counterlung position and the breathable volume within the counterlungs.
It is important to balance the volume in the breathing loop so that exces-
sive inhale or exhale pressure is not experienced.
Under certain situations the EXPLORER will vent during the exhaled breath.
This will result in a drop in oxygen levels and more gas addition by the
system.
It is possible to balance the loop to an extent by venting a small amount
through your nose, particularly on ascents if the need arises.
ADJUSTING THE BREATHING ‘FEEL’
The breathing ‘feel’ of EXPLORER is partially controlled by the LCV. Having
removed the case cover this can be seen underneath the Canister. This is
an adjustable valve (over a small range). Oriented as shown, moving the
valve left (Fig. 4.1, −) decreases loop volume (vents more), and moving
the valve right (Fig. 4.1, +) increases loop volume (vents less)
.
The LCV is a hydrostatically balanced valve, this means that in any swim
position it releases gas from counterlungs at approximately the same pres-
sure and rate. In addition it is a water drain device and it is connected to
the exhale counterlung via a water drain tube such that as water enters the
counterlung (condensed exhaled breath) then it moves through the tube
and out of the LCV regularly throughout the dive.
Fig. 4.1
−
+
LOOP VOL
UME