Under normal propagation and sea bed reflectibility conditions the equipment should be capable of measuring any clearance under the transducer between 2 m and 200 m.
The equipment should provide a minimum of two range scales one of which, the shallow range, should cover a range of 20 m, and the other, the deep range, should cover a range of 200 m.
The primary presentation should be a suitable graphical display which provides the immediate depth and a visible record of soundings. The displayed record should, show at least 15 min of soundings.
Other forms of display may be added but these should not affect the normal operation of the main display.
The pulse repetition rate should not be slower than 12 pulses per minute on the deep range and 36 pulses per minute on the shallow range.
The performance of the equipment should be such that it will meet the requirements of these performance standards when the ship is rolling ± 10° and/or pitching ± 5°.
5.1.7.1 More than one transducer and associated transmitter-receiver may be fitted.
5.1.7.2 If more than one transducer is used:
It should be possible to record on paper recording or other means the information about:
There should be means to retrieve the recorded information.
Based on a sound speed in water of 1,500 m/s, the tolerance of the indicated depth should be either:
whichever is greater.
The scale of display should not be smaller than 5.0 mm per metre depth on the shallow range scale and 0.5 mm per metre depth on the deep range scale.
An alarm signal - both visual and audible with mute function - should be provided when the water depth is below a preset value.
Alarm signals, both visual and audible (with mute function) to the navigator on the watch should be provided to indicate failure or a reduction in the power supply to the echo sounder which would affect the safe operation of the equipment.