Device that uses a sonic pulse to measure the depth of water below the boat.
alarm threshold setting
Knob for setting the maximum depth considered to be dangerous.
Knob for adjusting the amplification of the signal.
Button for activating the sounder and for selecting the scale.
Audible signal activated when the alarm threshold is reached.
Display surface where an illuminated dot appears at the point on the scale that corresponds to the depth.
Line graduated in feet or meters for reading the distance to the bottom.
echo sounder probe
Part of the sounder that is submerged to send the ultrasound to the bottom; it receives the echo and converts it into sound.
Electric wire that relays the electric signals between the housing and the echo sounder probe.
Metal prong that plugs into the housing.
Part of the echo sounder probe that emits the ultrasound and receives its echoes.