SSN NAUTILUS // FRAM STRAIT ICE PACK

BQS-8 Under-Ice PPI Sonar

Active 3.5 kHz acoustic sweep mapping submerged pressure-ridge ice keels and deep sound-channel contacts.

KEEL DRAFT CLEARANCE: 44.2 METERS
SOUND VELOCITY: 1,439 m/s
CONTACTS TRACKED: 6 ECHOES