🎧 Voyage on the Dark Submarine | Underwater Sonar Ambience Sounds for Sleep - YouTube
Amazon.com: Ice Hunt: 9781721314058: James Rollins, Ron Dryer: Books
What does a submarine active sonar really sound like? I've found a recording from the USS Caiman (BQS4), but I've read that real (modern) active submarine sonar sounds like a multitone range