1

PS: Talker identifier

2

IMDHB: Datagram identifier

3

hhmmss.ss: Coordinated Universal Time (UTC)

4

t: Transducer number

5

f,KHZ: Frequency (kHz)

6

x.x,M: Depth (Metres) The bottom depth is given as DBS (depth below surface). It is assumed that correct transducer draft has been provided.

7

y.y,DB: Bottom surface hardness (dB)

8

z.z: Relative biomass density in m²/nmi² (NASC) (sA) NASC means Nautical Area Scattering Coefficient. This is the format (sA m²/nmi²) in which we provide the biomass data.

9

,,,: Spare for future expansions