Heard Submarine While Diving?

[ystrout]

Hi,

Have any of you heard a submarine while diving?

I was diving La Jolla shores this weekend and heard either a submarine or a boat. I was at the ledge where it drops off into La Jolla Canyon and gets VERY deep. I know Scripps and UCSD always has submarines out there, but I'm guessing they stay pretty deep.

I was in about 60 feet of water. I heard the quit noise for most of the dive then it was extremely loud and like a high pitch engine. I have heard boats before, and they seem to have more of a rumble, and aren't quite as loud. Also, the only boats that really come into the area are lifeguard boats and there was none that day...

So my questions:
1. How far does sound travel underwater and stay loud? Would it be possible to hear a sub in about 150-200 feet of water?
2. Has anyone heard subs in marine reserve trenches before? I know they're there... It has to be called submarine canyon for a reason...

It was very possibly a boat, but they are rarely over the dive area so I'm just wondering about all possibilities.

 

[Doctorfish]

Military submarines should be pretty quiet. I've heard and seen the Atlantis
tourist sub on Grand Cayman cruise by at about 80-100 feet. Relatively loud electrical whine.

 

[Bob DBF]

As @Doctorfish said, military subs are quiet, in addition if you heard it, it would be in the lower frequencies and too close.

Private and research use electric motor drive and don't care about the sound they radiate. They use electric motors at higher speeds and will give motor and captivation whine but different and not as lous as a speedboat. I'm betting it was a speedboat.

Submarine (under water) canyon. U-boat is an anglicised version of the German word U-Boot,a shortening of Unterseeboot, literally "undersea boat", which makes it easy to see how, in the US, submarine is just shortened submarine boat. Since all of that shortening happened around 1900, it is easy to the confusion that might arise.



Bob

 

[The Chairman]

I encountered a sub back in 73 off of Ponce Inlet in Florida. Scary, scary. I heard a thrum first and it was bothersome. We finally saw it and it passed about 40 ft away.

 

[tursiops]

I know Scripps and UCSD always has submarines out there

Neither Scripps nor UCSD has a submarine.

1. How far does sound travel underwater and stay loud? Would it be possible to hear a sub in about 150-200 feet of water?

You can hear underwater sound a long way. The loudness diminishes with distance, of course.

It has to be called submarine canyon for a reason...

I hope that is not a serious statement.

What you describe sounds more like a jetski.

 

[ystrout]

Well they've used them for sure.... I guess if they don't own them they charter them.

And yes, it was a joke. Also, definitely not a jet ski. I'm been boating my entire life. We own the boat and a few people in our group have jet skis so I know what they sound like from underwater.

Could have possibly been a boat that the people I talked to didn't see.

 

[Saltyhawg]

We had one come close enough to see the people waving at us on a night dive in Cozumel. They do tours of Chankanaab(I think). It really didn't make that much noise as I recall. Pretty cool to see that, especially at night.

 

[broncobowsher]

Another diver running a scooter?

 

[aquacat8]

Aliens, definitely

 

[azstinger11]

Saw this guy on my trip to Aruba.

Not exactly Down Periscope or The Red October but pretty cool to see.

Also my guess it was one of the lifeguard boats that no one in your group noticed. They wouldn't get much attention scooting around out there by anyone, so easy to overlook. See them all the time out by the shores/cove.