Boat Builder Central - Builder Forums

Here's a good one for ya! I finally got my boat out to fish after getting it finished and after I stopped the engine and started fishing I heard a noise that sounded like bacon frying. My fishin' partner heard it too, so I know I wasn't losin' it. The sound was not coming from the fuel tank but the hull. I heard it in the aft end and also in the bow. Water temp about 72-75degrees and the air was about the same. The boat has been out in the sun before and it has been many months since its been painted. The color of the interior is San Juan tan. Is this typical of epoxy? Has anybody else experienced this? Also, I was only able to get only 16mph(gps) with a 30 hp. I installed a hydrofoil and am still getting some off and on cavitation. I have the cavitation plate even with the top of the tunnel when the jackplate is fully raised. It will still cavitate if I drop it just a little. Does that speed sound about right? I'm considering getting my prop cupped next.

How loud a sizzle? How big a piece of bacon? One area or all around the boat? Only when on the water after stopping, or even on land afterwards? I have a few ideas, but I don't know yet exatly what you are hearing, or where, or when... Did you have a cooler, or a bottled drink that was gurgling through its cap or cover? I've heard capped jars make the strangest LOUD sounds for over an hour as they heated up. Cavitation bubbles can bubble up around the hull and sound like bacon as they pop, when you stop, but they eventually subside as they all slide up along the hull to the surface. Do you have a live well pump going through a thru hull below the water line that could be pumping out cavitation bubbles? Are you hydrating yourselves while fishing, with tequila?

Joking aside, a better description? Was it only aft end and bow?

On a warm day... after stopping... dive under the boat with a diving mask and see how many bubbles are creeping along the hull. My glassed cuddy is incredibly acoustic, like a sound box on an acoustic instrument. If you've got the creeping bubbles... well... ok... I'm going too far! Maybe?

The sound is shrimp

Just an idea, are you running over something, perhaps some kind of sea grass or something that's tickling the underside of the boat and sounds like bubbles. Also, around here, disturbing the sea floor (lake bed) or the plants within can release gasses that bubble up and sound like sizzling.

Also, check battery location. Sometimes batteries can get very hot and they too can start to sizzle. And wet electrical can sizzle.

Air trapped in the tunnel?

Chupacabra?

My best guess is CO2 bubbles from grass, or mud

I occasionally hear sounds from my GF18 too...

It sounds like small little crystals cracking. I almost think think of it as salt crystals forming on the hull, but I'm pretty sure that's not it as I'll hear it in fresh water too.

I woulnd't descrbe it as bacon frying, but the description was close enough for me to speak up. So far I like Evan's idea about shirmp but it doesn't explain the fresh water...

Jason

I-T-'-S A-L-I-I-I-I-V-E !

BOOO HOOO HHOOO HAA HAAAAA Haaaa haa

they are trying to make contact....


Boo Radley clammin' under the boat with a snorkel, and a knife?


take a peek with a diving mask. when you find nothing, it will only deepen the mystery... tie your self to the boat with a safety line... just in case...

remember, any container that is *almost* air tight can sizzle. I wonder if foamed *sealed* compartments can vent in or out with such a sound?

bait fish flatulence?

Boy, I knew you guys would have fun with this one. Jason, I think we are experiencing the same noise. It was a crackling, bacon sizzling kind of noise that sounded like it was coming from the hull. I was sitting still in 6 ft of water at the time and moved over a mile and still heard the same sound. It was coming from the hull from the stern to the bow. It's not the battery and I didn't have any carbonated beverages. It did sound like it was being telegraphed through the plywood in the floor. I'm pretty sure it wasn't a chupacabra or Boo Radley. It does not occur on the trailer. You could hear it when it was calm and nothing was running and when the wind picked up later on you almost couldn't hear it. It sounds more like a crackling,sizzling noise than a bubbling noise. Thanks for your comments, no matter how humorous! Anybody out there check the speed on their XF20

double post

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Could it be hull slap in the tunnel? Where does the tunnel sit in relation to the waterline at rest? Is it completely submerged or does it rise above the water when you move in the boat?

Maybe you could rename your boat "Makin' Bacon"

I hear a similar noise. It is propellers from other boats echoing through the water. The hull amplifies it like a megaphone. It is a sizzling or whooshing noise. Rick

I have heard similar noise coming thru the hull while fishing at night. Stomping down on the hull would cause what ever it was to stop making the noise for a bit but it would start again in very short time. At least I knew that it was not the boat but something alive that responded to sound vibrations.

The noise is not from other props(nobody else around), and the top of the tunnel is above the water line(hull slap noise, not even close). This noise is continuous and Besides, when you put your ear close to the hull floor as you would do when you are trying to find the originating source of a noise, it is just as loud in the front of the boat as near the transom. Jacques, could this be a temperature/epoxy/fiberglass- expansion/contraction thing If it is, is this typical I do have foam in compartments on either side of the aft thwarts. I did drill a vent hole for them. and if it was them, you would think you would hear it when it was out of the water as well.
Joel, was the epoxy you sold me made by Kellog's? You know ,the Rice Crispy people
Thanks again for everyone's interest

I really have no idea what this could be

My best guess is that is an acoustical anomaly. Your boat has A LOT of surface area (hence the displacement and low draft). Maybe that large area acts similar to a membrane - like a drum. Amplifying any sounds underwater. I know when I’m swimming in the ocean I hear a lot of "clicks and pops".

A sole would muffle this – and if remember correctly you built your XF20 without a sole. Which would explain why other boats do not notice this. I built my boat with the same epoxy, and no snap, crackle, pop here

We need a sonar man, like the guy in “Hunt for Red Octoberâ€

I hear the prop noise even when there are no boats near. Water carries sound many times more efficiently than air. Rick

My sole is full of 2 part foam. I'm inclined to blame it on the foam, maybe air poping out of the little cells. Beats me.

I'll try to do more investigation the next time I hear it. Lately it's been too noisy on the Gulf to hear it.

Bit comforting to know I'm not the only one hearing this.

Jason

They're shrimp I'm telling you. I wasn't kidding.

http://www.studyworksonline.com/cda/con ... 1,00.shtml

You are not hearing anything. I repeat, there is nothing to hear.

HA!

It's auditory phantom sanding, like phantom pain for amputees...

The brain is permanently saturated with the sound of sanding and refuses to be denied it, like a constant soothing white noise...

And since you are now on the water, the brain accomadates its addiction by modifying it to a bubbly sound, so you won't suspect its in your own head, unless your head bubbles?

Snapping Shrimp? pfft! The simplest answer is not always the right one, or nearly as fun.

I know some will prefer Occam's razor, or *keep it simple sailor*, but should we ignore Crabtree's Bludgeon?

'No set of mutually inconsistent observations can exist for which some human intellect cannot conceive a coherent explanation, however complicated.'

If you don't see water coming in anywhere, let it sooth you... and ponder the most complicated explanation possible... Once you are assured it has nothing to do with a fuel line or other imminent danger...


Another idea... if someone has an inflatable or kayak, bring it along and then paddle out about 20 feet to see if it was your boat or environmental. I still will not quickly discount how acoustic my cuddy is with glass sheathing, which Jacques restated since your poor boat has no soul, I mean sole...

the mystery continues... the game is afoot...

I hope you're catching fish in the mean time?

If you're hearing it out in the grass beds in your area, I wouldn't be surprised if it is pistol shrimp. The sponges are full of the shrimp, and I hear them constantly when I'm scalloping or getting stone crabs.

Jason's observing the same phenomena confirms (to me) that it must have to do with the boat being wide/flat and having no sole. All our boats have soul

What we have stumbled across is a low cost, but highly effect underwater listening device. It gives a new meaning to the "X" in XF20.

JimW needs to know about this, his Navy guys in Jacksonville need XF20's not P3's.

Shine wrote:What we have stumbled across is a low cost, but highly effect underwater listening device. It gives a new meaning to the "X" in XF20.

JimW needs to know about this, his Navy guys in Jacksonville need XF20's not P3's.

I do tend to go with this explanation, even if it does not give the exact detail of the source of the noise. I had to grind a fillet in the glassed cuddy. The sound reflections were incredibly loud and nerve racking.

Simple carpeting on the floor may dampen it, if these hunches are correct. The carpet will also help the fish hear less of you.

ks

I'll let you decide whether my boat has soul, but it definately has a sole with lots of your marine foam under it.

It's a really weird sound. I've heard engine noise from other boats coming through the hull, definately not that. It definately could be shirmp, but I'd expect the sound to be muffled slightly if it was coming from under the hull. This is a VERY crisp sound that seems to come from the entire boat, not just the sole. That's why I thought it was salt crystals forming (I'm from MN, so this salt water stuff is still new to me). But I _think_ I've heard it in the Everglades fresh water too, which (if I'm remembering right) kills the salt water and shrimp idea.

You know those "pop rocks" things you throw and make a small explosion on the sidewalk? It sounds like one of those but 1/10th the size and coming from all over the surface of the boat. Maybe 10 or so a second. Kind of like little crystals are being cracked apart.

"Sandy Claws" Rice Crispy analogy is pretty accurate too.

Jason

BTW: I don't believe in UFO's or Big Foot.

EDIT: or Skunk Ape...

You were in the Everglades.... it was probably the Skunk ape.

Sorry, jason I was thinking GF16 for some reason. Your boat has sole

I'm with Evan. It's shrimp. Very common to hear that on all types of hulls around here. Especially loud with aluminum.

Cracker Larry wrote:I'm with Evan. It's shrimp. Very common to hear that on all types of hulls around here. Especially loud with aluminum.

I mostly fish in the 10,000 islands area and I've never once caught a shrimp in my cast net. I never gone looking for them, so maybe they're their, but I've never seen them.

I've decided to take the boat to the lake and I believe like Jason I will still hear the noise. If I don't I will check with the marine biology center here, I believe it is on the Salt river.
I think the reason this noise is bothering me so much is after being a mechanic for many years, a noise usually means trouble. Repairing work and police vehicles I've heard and seen things that never turn up on normal vehicles, and I've always located the problem. I hope this will not be the first one that I can't discover. I just hope that it is not like the old saying: that on a quiet night you can hear your Ford rusting!
I checked that link on the snapping shrimp. Have you ever seen shrimp with one large claw like a hermit crab while scalloping Evan? I'm not challenging,just asking because I don't know. I'm a desert rat!
Don't you just love a mystery? I would too if I knew for sure, it wasn't something bad

double post

Those "snapping shrimp" seemed to be something that live up in the northern waters. Never seen them in these parts.

Those "snapping shrimp" seemed to be something that live up in the northern waters. Never seen them in these parts.

Cracker Larry wrote:I'm with Evan. It's shrimp. Very common to hear that on all types of hulls around here. Especially loud with aluminum.

Well, now you know with aluminum that it is not the sound of epoxy getting microstress fractures! That should be a comfort somewhat. Thanks for that info Larry. Is there floatation foam on those aluminum boats?

I think if we could hear salt crystals forming, we could also hear the grass growing and fruit flies breathing... and the sound of one hand clapping...

The mystery continues, with or without a sole...

bottom machine transducer?

That could be it. Mine certanily makes lots of little clicks.

Switch off all power, all gadgets, and the battery switch(s) to off. Still there?

Didn't think about the sonar depth machine. Do they make an audible sound? I don't remember hearing anything in my bass tracker. I will try turning that off though. Thanks!
When and if I do find the noise, I will let everyone know

Yes the transducer will make a regular clicking noise. Very similar to dolphin(porpoise) clicks, but at a regular frequency.

Barnacles, oysters, shrimp and other critters make more of a crackling, sizzling noise that sounds a lot like bacon frying. Freshwater mussels may do that also. Sound travels so well through water and some hulls act as a speaker or sounding board. Seriously. I doubt the boat has a problem.

Here are a couple of reference articles to hopefully prove I'm not completely nuts.........a google search will give you plenty more.

http://www.boston.com/globe/search/stor ... 109982.htm

http://www.dosits.org/animals/produce/1i_2.htm

http://www.timespub.tc/Features/Archive ... ilence.htm

http://www.48north.com/may2001/letters.htm

Next time you hear the noise stomp on the bottom of the boat and see if it doesn't stop for a few seconds. If it does you know it's something alive and responding to your noise. If heard this many times in shallow back waters of Mosquito Lagoon.

Snit, snit, ack, ack! Protect the queen damnit!

I wouldn't be at all surprised if it were something organic making these noises. Either weed and bottom muck or shrimp or something else.

I am perplexed! I may never find out what caused the noises. I took the boat out on the St. Martins River and did not hear any noises....and I had the sonar on too! I was out in the gulf somewhat in the weeds as well. Maybe it is something biological in the Shell island area

Good part about it is you have ruled out it being your boat, correct?