Noisy boats

[David in Sandusky]

Shock cords on halyards. Drop pennant and flags that may strum on stays. Take down a manometer that scraps against the bulkhead if the boat is rocking. Loosen or reset dock lines if fenders groan.

If there is a repetitive sound, we figure it out, and address it. Can't do anything about the mating fish bumping against the hull at our dock in the springtime, though. Or about wind whistling in the rigging. We have moved our anchor when we are too close to another boat that thinks their music blared out from the cockpit sounds lovely to all.

 

[dLj]

Can't do anything about the mating fish bumping against the hull at our dock in the springtime, though.

You've just reminded me of the sound of barnacles at night on my hull. They must have been feeding, you could hear them making crackling sounds. Took.me some time to figure out what it was. When I cleaned them off and the sound stopped - it was cleared up...

dj

 

[rgranger]

... you could hear them making crackling sounds. ..
dj

That is interesting. I have not had that one before. I work with a guy in our Biology department who is a renowned barnacle expert. I'll have to ask him if he knows what causes that sound.

Edit: So I sent an email to my barnacle expert friend. I'll let you all know if he gives me some interesting info.

 

[dLj]

That is interesting. I have not had that one before. I work with a guy in our Biology department who is a renowned barnacle expert. I'll have to ask him if he knows what causes that sound.

Edit: So I sent an email to my barnacle expert friend. I'll let you all know if he gives me some interesting info.

Now that will be VERY interesting! Do post his response. All I know is when I cleaned them off, the noise was gone...

dj

 

[Windpilot]

It's simply tiny crustaceans eating stuff on your hull.

 

[dLj]

It's simply tiny crustaceans eating stuff on your hull.

Just realized I had pollicipes pollicipes - or goose neck barnacles on my hull. Just a FYI....

Might help you barnacle expert....

dj

 

[rgranger]

Now that will be VERY interesting! Do post his response. All I know is when I cleaned them off, the noise was gone...

dj

This is what I heard back...

Well, that is an interesting thought, but I have to say “no”. Barnacles feed by stroking feathery appendages (cirri) through the water to strain out particulate food. The limbs extend by hydraulic pressure, essentially through squeezing the “blood” (actually hemolymph). Then they retract by contraction of small muscles throughout the limb. Neither of these actions makes any noise to speak of. I have stayed up all night watching barnacles feed in a flow tank, and I never heard a noise. Now, I could imagine the rugosity of the shells on the hull might influence the sound the water makes at the waterline. Alternatively, and more likely, there is some critter feeding on or around the barnacles making the noise. Some fish make crackling noises, but my guess is pistol shrimp (a.k.a. snapping shrimp) living in the crevices of a well-developed barnacle colony (especially in tropical water). When I go snorkeling on coral reefs in the Caribbean, I hear them almost everywhere and continuously. They snap the dactyls of there claws to stun prey and to communicate about territory. It is actually a really cool phenomenon, the snaps cause cavitation bubbles that explode and release sound and light energy (soniluminesence).

Here is a link that has a sound clip.

https://dosits.org/galleries/audio-gallery/marine-invertebrates/snapping-shrimp/#:~:text=Sound%20is%20produced%20by%20the,produced%20when%20the%20bubble%20collapses.

 

[dLj]

This is what I heard back...

Well, that is an interesting thought, but I have to say “no”. Barnacles feed by stroking feathery appendages (cirri) through the water to strain out particulate food. The limbs extend by hydraulic pressure, essentially through squeezing the “blood” (actually hemolymph). Then they retract by contraction of small muscles throughout the limb. Neither of these actions makes any noise to speak of. I have stayed up all night watching barnacles feed in a flow tank, and I never heard a noise. Now, I could imagine the rugosity of the shells on the hull might influence the sound the water makes at the waterline. Alternatively, and more likely, there is some critter feeding on or around the barnacles making the noise. Some fish make crackling noises, but my guess is pistol shrimp (a.k.a. snapping shrimp) living in the crevices of a well-developed barnacle colony (especially in tropical water). When I go snorkeling on coral reefs in the Caribbean, I hear them almost everywhere and continuously. They snap the dactyls of there claws to stun prey and to communicate about territory. It is actually a really cool phenomenon, the snaps cause cavitation bubbles that explode and release sound and light energy (soniluminesence).

Here is a link that has a sound clip.

https://dosits.org/galleries/audio-gallery/marine-invertebrates/snapping-shrimp/#:~:text=Sound%20is%20produced%20by%20the,produced%20when%20the%20bubble%20collapses.

Must have been snapping shrimp! That is the sound! But I wonder why when I cleaned the hull of the goose neck banricles the noise went away. Perhaps the shrimp were attracted to the barnacles in some way?

dj

 

[Dalliance]

My halyards are internal and the main halyard becomes a topping lift at the dock used in combination with the mainsheet to limit boom movement. The mast has a raceway for electrical wires, so there’s nothing hitting the mast inside or out.

My club burgee line attachment used to pluck the shroud like a guitar string until I changed the attachment point to a soft shackle through the turnbuckle. I still have to take it down on especially windy nights though because the flag slaps against the shrouds in some wind directions.

Dock fender squeaks are mostly eliminated by fleece fender covers and I have bow and stern line snubbers to prevent jerking when the wind pushes the boat off the dock. The longer springlines are triple braid for added stretch.

Plates stored vertical in their galley locker bin sometimes rattle but I solve that by stuffing in a spare dish towel. The boat is otherwise pretty free of creeks, squeaks and rattles. At least ones that I can hear anymore.

Waves slapping the stern in a stiff north wind don’t bother me sleeping up in the v-berth. I kind of enjoy the sound of wind through the rigging, though if it’s from the north or northeast it often predicts a boat chores day rather than sailing here.

What I don’t enjoy is the inconsiderate loud music and wakes from the power boats that come in between midnight and 2 or 3 am. I’m on a T-head dock along the main channel, so I get the brunt of it. Not much to be done about it except report the most egregious repeat offenders to the Harbor Master, which I haven’t bothered to do….yet.

 

[thinwater]

You've just reminded me of the sound of barnacles at night on my hull. They must have been feeding, you could hear them making crackling sounds. Took.me some time to figure out what it was. When I cleaned them off and the sound stopped - it was cleared up...

dj

It was not the barnacles. It was shrimp hunting on the hull. https://en.wikipedia.org/wiki/Alpheidae

Either way, no barnacles, no noise.

 

[dlochner]

We were in Oriental a couple of years ago and the croakers were in the marina. It was not a restful night's sleep.

 

[Bob S]

The wife complains of my snoring. The only sound I hate is when I pick up a mooring ball and the wind/current causes it to bounce off the side of the hull.

 

[All U Get]

The wife complains of my snoring. The only sound I hate is when I pick up a mooring ball and the wind/current causes it to bounce off the side of the hull.

Mine said yelling when I have fallen overboard is very irritating.

 

[shemandr]

[QUOTE="dLj, post: 1808599, member: 137544”] Must have been snapping shrimp! That is the sound! But I wonder why when I cleaned the hull of the goose neck banricles the noise went away... [/QUOTE]

No barnacles. No feeding shrimp. No noise.