Abyssal Watch — Passive Array 4
Sonar Scope
Live bearing plot for the Kerrow Trench listening station. Beam period 8 s, true north up, contacts held for three consecutive returns.
Abyssal Watch — Passive Array 4
Live bearing plot for the Kerrow Trench listening station. Beam period 8 s, true north up, contacts held for three consecutive returns.
K-114 · Charted traffic
Steady screw signature, six blades, cavitating lightly on the up-swell. Matches the Peterhead registry return logged three watches ago. No manoeuvre since acquisition.
| Parameter | Value | Trend | Confidence |
|---|
Element 33 still showing 4 dB of self-noise on the low band; compensation curve applied at the beamformer rather than the pre-amp. Flagged for the maintenance boat on Thursday.
Broadband hiss with no tonal ladder. Classified unresolved for two returns, then flagged when the bearing rate went flat — a flat bearing rate at that range means it is closing on us bow-on.
Seasonal fin whale calls between 190° and 215°, twenty-hertz pulses at roughly ten-second spacing. Masked U-013 for most of the watch; the operator switched to the narrowband waterfall to hold it.
Two flagged tracks, two unresolved, five charted. Recommend keeping the beam period at eight seconds until the trench current slackens near dawn.