3.8
Deployment scheme
The anchoring scheme used is very dependent on the goals of the data collection in combination
with the deployment environment. Thankfully
SoundTraps are more easily deployed than traditional
acoustic recorders due
to their small size. A SoundTrap’s
weight in water is approximately 0.5 kg.
Most often the hydrophone is located near the sea
floor, using an anchored line. This involves running a line
between a heavy anchor weight and either a surface or
sub-surface float. A sub-surface float is often best, as it
is less affected by weather/swell and is less likely to be
tampered with. The SoundTrap should be attached to
the line a couple of meters off the bottom. Two grooves
in the housing circumference provide attachment points
for cable ties for this purpose. Do not use hose clamps
or any other fastener that will place clamping stress on
the housing as this may cause damage. There are also
two lanyard attachment points which can be used to
provide additional security/redundancy.
Ensure there are no metal objects in close proximity
(3cm) to the SoundTrap wet connector eg using metal
brackets or wire rope. Doing so may lead to galvanic
corrosion (and eventual failure) of the stainless steel
wet-socket body.
Don’t mount your SoundTrap
so close to the sea floor
that it may become covered in sand or mud. This will
also lead to corrosion and eventual failure of the wet
connector.
Be mindful that a taut line combined with strong currents may result in ‘cable strum’ which may
disrupt your recordings. In this case a rigid frame may be more appropriate.
Figure 5 - Typical deployment including external
battery