Underwater Acoustics, Sonar, and Subsea Positioning: Sound Speed Profiles, SOFAR Channel, Multibeam Echosounders, Side-Scan Sonar, and USBL/LBL Subsea Acoustic Navigation

Deep End Era. Engineering with Sankalp · Oct 29, 2026 · 1h 13m

Because seawater is an electrical conductor that blocks radio, radar, and GPS within centimetres, sound is the only long-range window into the ocean. We build underwater acoustics from first principles: sound speed profiles, the SOFAR waveguide, Urick's sonar equations, boric acid and magnesium sulfate absorption, Multibeam vs Side-Scan Sonar, and USBL/LBL subsea navigation.

Chapters

00:00:00 Opening: Two Thousand Two Hundred Metres Below the Norwegian Sea

00:04:36 The Speed of Sound in Seawater: Temperature, Salinity, Pressure, and Snell's Law Ray Refraction

00:10:14 The Deep-Ocean SOFAR…