Feature Sound: Ship Noise

Photo Copyright Tom Kieckhefer

When I was young, I so wanted to learn how to scuba dive so that I can visit with the whales. At the time I thought that I’d be swimming in the quiet, majestic presence of these mighty creatures. Fortunately, many years later I did learn to scuba dive, but I have yet do so with any large whales. The first surprise I had diving was that the ocean is not quiet. There are lots of sounds. Unfortunately, the loudest sound in the beginning was always the racket coming from my scuba equipment. Scuba divers sound a lot like Darth Vader with bubbles that rush past your ears. Only the loudest clicks and snaps from fish could be heard over the noise. But one type of sound always managed to drown out my equipment; the sound of a passing small motorboat or ship.

If you have ever had a mosquito buzzing around your ear, you know sort of what a small outboard motor sounds like. Small boats have a high-pitched whine that makes you feel like you’re about to be run over by a big mosquito. Because sound travels so much faster in the water, you cannot tell what direction the sound is coming from, so you don’t know where the boat is. I would always start looking around for the boat, but sound also travels better though water so it’s possible that the boat was a long way away. I never see any of the boats I hear, but it always sounds like they’re right on top of me.

Big ships are a different matter. They sound like a low deep rumble that has another low pulsing sound mixed in with it. You almost feel the noise more than you hear it. Since I tend to scuba dive in places that are too shallow for big ships, I know that I’m not going to be run over, but again the sound is coming from everywhere. The few times I’ve surfaced to see what was making all the noise, I’ve always been amazed at how far away the ship is. Sometimes they look like they’re a mile away. If you have ever heard a car blasting loud music with the base thumping away, but the car was not all that close to you, you’re experiencing a quiet version of some big ships.

Since I can only visit the underwater world for short periods of time, and I always hear 1 or 2 boats, I’m glad I’m not a fish. Places like Narragansett Bay have lots of pleasure boats and big ships passing through. It must be like living near an airport. It’s loud down there. I still hope to get to dive with big whales, but my dream has been altered because I now know that any songs or sounds that the whales might produce will also be accompanied by the sound of the ship that brings me there. Hopefully the open ocean is a bit quieter for the whales.

– Glen Modica

Merchant vessel CERES (above, right) in the St. Lawrence, CA. Recorded as vessel was approaching from 1.7 km (1 mi) away. Sound courtesy of Peter Scheifele, Department of Animal Science at University of Connecticut.