Maddening night time noise

[chowdan]

My high bilge water alarm sometimes hums oddly. It's almost like it is trying to trigger, but isn't enough for it to go off so it creates a slight hum. Though likely not enough to make someone notice unless they are paying attention to it.

On a side note I've had knocking sounds on the keel at night when I first moved aboard. Still have yet to figure out what in the world it was since when I moved aboard was less than a week from time of launch.

I would disconnect the battery on my boat and if the sound is still present I'd chalk it up to being something outside the boat and learn to live with it until I moved elsewhere. I find the sounds of boats are no more noisy than living in a city.

[hpeer]

When I dove on the boat in St Martin we had some soft fuzzy growth on the bottom. No biggie. But on the keel there were a bunch of places where the growth had been rubbed off. It looks almost like what you would get if you shipped it with a piece of rope. Clearly something largish has been glancing off the keel. We’ve never heard it. I’m guessing it’s some kind of predator fish after critters munching on the growth.

[Pelagic]

The funny thing about noise and boats is..

The quieter the boat, the more you hear!

I love the quiet, but my ears pick up every sound within range and the brain analyses it for potential dangers. That is what you become conditioned to do.

Ironically, after my ER refit where I completely sealed the space with heavy Sounddown materials. I can no longer hear the fresh water pump cycling on and off.

That bugs me as I worry about a broken line and I miss that reassuring noise turning off

[Bill Streever]

Yup, probably biological. In Honduras two years ago, what turned out to be toad fish under the boat (once we knew how to find them, we found them in holes everywhere on that bottom) kept waking us up. Apparently they have a mating call.

On the other hand.... Here in the mooring field in Bonaire, the underwater noise from cruise ships sometimes wakes us up, even thought we cannot hear them on the surface.

If you are interested enough, you can rig a cheap hydrophone (underwater microphone) pretty easily. I am sure there are designs on line. Mostly you will just hear boat noise but in some areas you'll hear various fish, shrimp, dolphins, whales, gravel rolling on beaches, etc.

[a64pilot]

Originally Posted by Suijin

I’m in Vero right now. I’ve heard a pinging/crackling/snapping sound at night. Assumed it was shrimp.

It is.
I had a friend that had just bought a steel boat, for a few nights he was convinced that it was the bubbles coming off his hull from stray current
Then I guess he realized it was only at night and figured it out.

[senormechanico]

Originally Posted by Pelagic

The funny thing about noise and boats is..

The quieter the boat, the more you hear!

I love the quiet, but my ears pick up every sound within range and the brain analyses it for potential dangers. That is what you become conditioned to do.

Ironically, after my ER refit where I completely sealed the space with heavy Sounddown materials. I can no longer hear the fresh water pump cycling on and off.

That bugs me as I worry about a broken line and I miss that reassuring noise turning off

A very basic electronic circuit will let a water pump (or whatever intermittent device you fancy) run for a pre determined time, but if it runs too long, it will stop and sound an alarm.
1 capacitor, 1 relay, one resistor. one transistor and a piezo alarm is about all you need.
An added advantage is when you have a guest who loves a LOONG shower, they get the message when the water shuts off and sounds an alarm.

[Stu Jackson]

Originally Posted by Pelagic

>>>>>>>
>>>>>>>>>>>>>>>>>

I love the quiet, but my ears pick up every sound within range and the brain analyses it for potential dangers. That is what you become conditioned to do.

>>>>>>>>>>>>>>
>>>>>>>>>>>>>

That's why I can't wear ear plugs, or even headphones/earbuds. I NEED to hear what's going on.


I sleep great on the boat.

[SailFastTri]

Originally Posted by SeaBreeze-1

I used to have a humming noise (sounded a bit like a UFO) on a previous sailboat that took 3-4 years to find. It turned out to be the topping lift on the end of the boom. I also parked my main halyard there when not in use. A couple of turns around the topping lift with the halyard, before snugging it up and the noise stopped. If yours only happens at night, it more than likely is critters. Do any other boats around you hear it as well?

"Sounded like a UFO" and nobody is questioning that? Does everyone else reading this thread know what a UFO sounds like?


If you all know I must have missed out in my life experiences... now I really am curious.

[Pelagic]

Originally Posted by senormechanico

A very basic electronic circuit will let a water pump (or whatever intermittent device you fancy) run for a pre determined time, but if it runs too long, it will stop and sound an alarm.
1 capacitor, 1 relay, one resistor. one transistor and a piezo alarm is about all you need.
An added advantage is when you have a guest who loves a LOONG shower, they get the message when the water shuts off and sounds an alarm.

That's a great idea.....can you buy them already made up for a 24v device?

[Sojourner]

On Wake, the source of maddening night time noise is 100% always caused by our rather annoying infestation of cats.

[OldGreyB]

"Try this. Time it. If is PRECISELY on some routine it’s most likely electrical.
If it is and you are desperate, disconnect the battery to see if that silences it."

Your answer to hpeer's suggestion above would indicate that it is electrical not biological:

"The noise starts shortly after dusk with a single crip or ping ( sort of like a hum as a motor starting) about every 30 seconds After an hour or so it pings twice in succession about every two minutes. This double ping will last till dawn."

Since the issue has arisen after a period away from the vessel and you have solar, are you sure all your batteries are now fully charged? Do you have a separate battery monitoring device such as a xantrex etc? These have low voltage alarms on them with adjustable set points. If your battery system is not fully charged and at night your fridge and freezers are running, with the removal of the solar charge your total battery voltage may be going below the set point on the battery monitor and hence alarming - with the frequency change as the voltage decays after the first hour. Alternatively the solar charger could be hunting for voltage (none due to any sun) and could also be alarming due to low total system voltage. Check and post model of battery monitor and solar system charger and that may help the forum resolve.

Also as per hpeer's suggestion, try disconnection of the negative on the house battery for an hour after sunset and see if all is quiet.


"I don’t have a anchor light."
BTW you need for your own safety an operating anchor light....

[mfeene01]

Had a similar situation a few years back. Only heard it at night. Drove me nuts. Did a LOT of searching and testing. Turned out that a boat with "electronic anti-fouling" had come into the marina.

MikeF

[senormechanico]

Originally Posted by Pelagic

That's a great idea.....can you buy them already made up for a 24v device?

I'll draw a diagram soon and post it.

[hellosailor]

"I NEED to hear what's going on." I'm with you, Stu. This is genetics and evolution. Our ancestors were not eaten by lions or bears sneaking up in the night. It can be a PITA on the hook in a strange place, where I'll come briefly awake if the wind shifts, tide turns, moon comes up bright from behind the clouds...but at times that "gentle bump" also meant another boat was swinging into us.
No lions or bears, YET.

[senormechanico]

Here's the diagram for the water pump cutoff and alarm.