Mysterious Humming Sound

[Lightwave99]

Do you know what this weird humming noise is? We were up in Desolation Sound and Pendrell Sound on the British Columbia coast this June (about 100 miles north of Vancouver), and a few times we heard a mysterious humming noise. It was not our rigging! We could particularly hear it in the hulls of our catamaran. We know we were not imaging it as when we were in Oyster Cove at Pendrell Sound, a fellow who had just anchored a little ways away from us rowed over and asked us if we had heard this humming sound. He had heard it the night before at a nearby anchorage just before he came into Pendrell Sound.

The sound was continuous starting about 9 o'clock at night. It was continuous, never varied in pitch and and seemed to stop abruptly around 4 or 5 in the morning.

We wondered if it might be fish-farm related, but the fish farms are a long ways away. We know that in Robson Bight up here there is an ongoing whale/Orca study and we wondered if that might be the source, but that would be a long ways away and we doubt they would do such a thing as it would only disturb the Orcas, whales and dolphins.

We have done a bit of web surfing and it seems to be an international phenomenon. Does anyone have any ideas what it could be?

[Tetepare]

Probably shrimp. They’re behind most noises.

[Lightwave99]

It's not shrimp!!! We know full well the snap-crackle-pop sound of shrimp on the hulls, having experienced it first hand when we were in the Sea of Cortez, Mazatlan and Puerto Vallarta and all places in between... This is a humming sound, like if you were to hum and try to tune your ukulele... a steady continuous hum.

Anyone else have any ideas? Let's solve this problem! If it is man-generated, it needs to be stopped.

[Pete7]

Gentlemen a few posts deleted. Please remember our 'be nice' rule on the forum.

[JPA Cate]

Hi, lightwave,

We have a steady hum at 17 knots of wind when one of our running back stays will vibrate. I do realize you said it was not from your rig; and that someone else mentioned the humming to you; and a rig hum from one boat is not likely to be heard on another.

Have not ever heard said hum, but have read recently that some of the studies on orcas do use sound, and sound travels a long way through water. It being steady, as you described, and then just turning off does make one suspect something man made.

Sorry, this isn't help exactly, just encouragement to query the coast guard, who may know what's going on, even if it isn't their noise. Also, fishermen may have an idea, 'cause they're out in all weather.

Do you, by any chance know what pitch the hum has? C below middle C?, or even better in frequency (Herz) and intensity (decibels--at your location).

If you're in an area with some other boats, you could make a day trip out of it, see if you can triangulate to where it is loudest then all approach it. It will get somewhat louder near the source, but remember whale song and other sounds transmit a long way through water.

Ann

[ItDepends]

Midshipman. The fish.

https://www.youtube.com/watch?v=nNB-hoKwa0A

[flightlead404]

Originally Posted by ItDepends

Midshipman. The fish.

There's enough weirdness in reality without having to make stuff up!

[Lightwave99]

Thanks to ItDepends and Flightlead, but it is a much higher pitch than the Midshipman Fish. Very interesting, though. Next time we hear it, we will try to record it, but I think it may be too faint to record.

[Lightwave99]

Originally Posted by JPA Cate

Hi, lightwave,

We have a steady hum at 17 knots of wind when one of our running back stays will vibrate. I do realize you said it was not from your rig; and that someone else mentioned the humming to you; and a rig hum from one boat is not likely to be heard on another.

Have not ever heard said hum, but have read recently that some of the studies on orcas do use sound, and sound travels a long way through water. It being steady, as you described, and then just turning off does make one suspect something man made.

Sorry, this isn't help exactly, just encouragement to query the coast guard, who may know what's going on, even if it isn't their noise. Also, fishermen may have an idea, 'cause they're out in all weather.

Do you, by any chance know what pitch the hum has? C below middle C?, or even better in frequency (Herz) and intensity (decibels--at your location).

If you're in an area with some other boats, you could make a day trip out of it, see if you can triangulate to where it is loudest then all approach it. It will get somewhat louder near the source, but remember whale song and other sounds transmit a long way through water.

Ann

It is not something that is heard on the exterior of the boat. We hear it inside the hulls, and it definitely is not our rigging. We know what whale song sounds like and it is not whale song--which goes up and down--it is a consistent hum on the same note. But it is definitely there until 4 or 5 in the morning and then it stops abruptly. thanks for your suggestions, though, Ann!

[Franziska]

Sounds like a shoreside underwater pump or turbine.

Are there any water power stations with a reservoir close by?
They may pump water up with "daylight" electric power and have it go through a turbine at night to produce electricity at night.

Or tidal power turbines?

[Lightwave99]

Thanks Franziska for the good suggestion. We will look into it!
Cheers
Carllie & Garett on Light Wave
Vancouver, BC

[JPA Cate]

Originally Posted by Lightwave99

It is not something that is heard on the exterior of the boat. We hear it inside the hulls, and it definitely is not our rigging. We know what whale song sounds like and it is not whale song--which goes up and down--it is a consistent hum on the same note. But it is definitely there until 4 or 5 in the morning and then it stops abruptly. thanks for your suggestions, though, Ann!

So, at your latitude, it stops about sunrise? That's weird! I didn't think marine animals were particularly nocturnal.... Ah, well, lots in the world I don't know! Please share it with us when it is discovered. Thanks.

Ann

[s/v Jedi]

It’s probably the discharging of the super-capacitor inside the NSA tracker they put on your boat

[Viking Sailor]

Russian Sub!!!

[NPCampbell]

Knowing what the frequency spectrum of the noise would help. Download an audio frequency analyzing app on your phone and hold your phone against the hull. If it's a constant frequency or pulsating with constant precision then it's probably man made. i.e. 50/60Hz hum, etc.