Aquatech "Black Sea" Speargun Operating Instructions
October 2009 edition
Initial Preparation of "Black Sea" Speargun Prior to Charging
Enter the water with the spear removed from the gun and the automatic line release lever swung out to the open
position after pulling the plastic trigger to release it. With the gun totally submerged, or at least completely
submerged at the rear end, operate the hydropump lever to flood both the hydropump's narrow tubular body and the
gun's internal
"hydraulic locking chamber"
; five or six full strokes of the hydropump lever should be sufficient.
Next flood the speargun's inner barrel with water, if it has not already been flooded, by submerging the muzzle.
Then insert the spear into the muzzle and push it down into the inner barrel until it reaches the end of its travel. Very
little effort will be required as the water injected during this process will be exiting through the already open
"trigger control valve"
.
Note that the position of the line release indicates the status of the "trigger control
valve"; when the line release is open the "trigger control valve" is open, when the line release is closed the
"trigger control valve" is closed.
Now with the gun fully submerged pull the spear partially out of the inner barrel to about the half-way position and
then push it back in again. This action pumps additional water through the gun's inner barrel eliminating any
remaining air bubbles in the barrel and
"hydraulic locking chamber"
as the sliding "
O
" ring
spear tail relief valve
motion will allow more water to pass into the inner barrel from outside the gun when the spear is pulled forwards.
Repeat this spear pumping action once or twice to ensure the gun's hydraulic system is completely flooded and then
push the spear down to the fully inserted position.
Note that a completely flooded hydraulic system is essential to
the gun's shooting performance, so all air bubbles should be completely purged from the "hydraulic locking
chamber".
Next swing the line release lever back to the closed position, this resets the trigger and closes the
"trigger control
valve"
, you will hear the trigger click into position as it engages the slot in the rear of the line release lever. Closing
the
"trigger control valve"
completely seals off the
"hydraulic locking chamber"
which is the basis of the gun's
relatively silent shooting operation compared to that of other pneumatic spearguns. Now arrange the shooting line on
the front line hook at the muzzle and the line release lever at the handle in a series of line wraps so that the shooting
line is neatly stowed on the
"Black Sea"
gun. The gun is now ready for charging by working the hydropump lever.
Note that the line release must be in the closed position in order to charge the gun for shooting.
Charging the "Black Sea" Speargun for Shooting
Support the rear of the gun (while rolled onto its left hand side) against the right knee while holding the gun
horizontally across your body, one hand holding the forward barrel section of the gun while the other hand grasps
the front end of the hydropump lever. Adopting a slightly upright sitting position while floating at the water's
surface makes the gun hydropumping operation easier. With the gun fully submerged opening the hydropump lever
outwards injects water into the gun (
hydropump power stroke
) while closing the hydropump lever back against the
gun body (
hydropump return stroke
) sucks more water from the surroundings into the hydropump's tubular body.
Maximum shooting power requires a full set of hydropump lever strokes that have the combined effect of injecting a
cumulative volume of water equivalent to the inner barrel's internal volume. If necessary rest breaks can be taken
both between and during successive hydropump lever strokes as the hydropump system has a
"non-return valve"
to
stop injected water coming back out of the gun again. Lower power shots can be achieved by using less hydropump
lever strokes per shot, however water must then enter the inner barrel through the
"spear tail relief valve"
once the
compressed air driven internal water column ceases pushing the spear from the gun. Water flowing backwards
through the
"spear tail
relief valve"
minimises the suction effect developing behind the departing spear tail.
Basically the shorter propulsion distance for the spear in the inner barrel produces the lower power shot. The
momentum achieved by the spear up until the moment that the water column behind it ceases pushing the spear is
what allows the spear to exit the inner barrel, although at a reduced velocity.
To gain full performance from the
"Black Sea"
gun and the
maximum spear velocity
use the full number of
hydropump lever strokes indicated for your model of the
"Black Sea"
gun. Longer barrelled
"Black Sea"
guns will
require more hydropump lever strokes as a longer column of water is required to propel the spear under power for
the entire length of the inner barrel, hence the maximum number of strokes needed is dependent on the gun's inner
barrel length.
Cleaning the "Black Sea" Speargun after completion of the Dive
At the completion of spearfishing it is recommended that you purge any remaining saltwater from inside the gun.
There is always some saltwater trapped inside the
"hydraulic locking chamber"
after the gun has been used for
spearfishing in the ocean. The trapped saltwater can be easily replaced with freshwater without dismantling the gun
and by doing so you will minimise the possibility of internal corrosion occurring until you have the opportunity to
open the gun at the rear end for more thorough cleaning at a later time. The procedure used is identical to the
flooding of the gun described earlier, except that the rear of the gun should be submerged in a tub of freshwater so
