Sentry Manual Rev2.1
Copyright 2017, Nellis Engineering, Inc.
7
To turn the display off, tap the side of the housing 3 time. In the lower left corner “
OFF?
” will
appear to confirm that you want to turn it off. (Fig. 10) Tap the side 3 more times within 5
seconds to turn off the display.
Fig. 9
Fig. 10
Depth
(top left corner): Displays the depth in feet or meters with 0.1 unit precision. The depth is
compensated for altitude, provided the display is turned on before entering the water. If the
display is turned on while under water, it will revert to standard sea level calibration. The depth is
accurate to 425ft (130m) and accuracy may decrease slightly when below that. The Sentry housing
is rated for 660ft (200m),
Timer
(top right corner): When the display exceeds 3ft (1m) depth, the timer in the top right
corner will start running and continue to run, until the depth reads less than 3ft (1m). The timer
will reset if the depth reads less than 3ft (1m) for 3 minutes.
Watts
(center left) Displays the power that the motor is currently using in real time. The diver can
control the DPV to limit the power to that is required by the dive plan. By referencing a known
distance over a time period, the diver can estimate their speed based on the DPV power level for
their equipment configuration. More drag (i.e. drysuit, more tanks or towing articles) will require
more power to obtain a known speed and less drag (wet suit, single tank) will require less power
to achieve the same speed.
Watt-Hours
(center right) Displays the quantity of energy consumed from the battery(s). It will
begin counting up from zero and the closer it gets to your known battery capacity, the closer you
are to swimming your DPV back to the boat or shore, and no one wants that.
Do not turn off the
display until you are done diving for the day.
When the Sentry is powered off, the Watt-hours
used are reset to zero on restart.
It is initially recommended to fully charge your DPV battery and dive the DPV with the Sentry
until your battery cuts out, to know the true capacity for future dives. Do this in good conditions
and near your exit point or boat, when you get close to what you believe your battery capacity is.
