Chine slap at anchor

Saw a trawler in the mooring field here. This is how he gets rid of wave slapping on the bow. Just a write-up, nothing for sale.
Prevent Wave Clacking FREE | Stop chine noise/clacking/slapping from waves on your boat

I've seen this occasionally. In honesty, I never thought this was a 'problem'. Like listening to waves crashing when at the beach, or the wind through the pines up in the mountains, or crickets and frogs on a quiet summer night. But then I also don't understand the idea of trying to keep a boat from rocking at anchor either. After, all...it's a boat on the water, right?


My concern with this is potential for calamity. I like to keep the boat always in a state of 'readiness'. You never know when you might need to fire up the engines. It would be a tough night if the anchor drags AND one of these lines ends up wrapped in the wheel.

Tried it years ago. Didn't work worth poop.

Pete

That is a big reason to buy a boat with an aft or midships berth if you can.

I've had to anchor ass-first a few times to get some decent sleep. That does work, but has its downsides!!! Gets some funny looks, too.

Shrew said:

Snipped
My concern with this is potential for calamity. I like to keep the boat always in a state of 'readiness'. You never know when you might need to fire up the engines. It would be a tough night if the anchor drags AND one of these lines ends up wrapped in the wheel.

Click to expand...

The first thing that crossed my mind.

Most boats stern is far larger than the pointy end.

With a used sail boat winch mounted (great when docking) most anchor recovery is a snap.

Wind anchor loading is from the Sq Ft of boat exposed to the breeze , bow too or stern too its about the same loading.

This "chine slap" issue comes up regularly. Nordic Tugs are notorious for chine slap. I initially went the "preventer" route... effective, but a pain to deploy, a potential entanglement problem in storms, and silly looking to boot. I fixed the problem by filling in the chines with no effect on performance.

That is exactly the sound that puts me to sleep along with a sailboat halyard clanging back and forth on the mast.

Puffin,
I fixed the problem by filling in the chines...

We are new to our Mainship 34T and our only complaint is the noise sleeping forward - would love to find a reasonable fix.
Can you elaborate a little on your fill technique.
Did you start w/ a slab, foam core, etc - secure & fair it in or build it up solid from scratch?

We've slept in the bow of our sailboat for years and very few issues with noise. Now with our new, to us, Europa style trawler, the wave slap is definitely noticeable, especially when at anchor. When at the dock, we never notice it. It's good to see some others with the same slapping concerns. When the wind is really blowing and the boat is hobby horsing, I just have to move to the salon.

LOL...So that's what the noise is! I've got the same issue... Never a problem on our old sailboat, but with these spray rails it's really noticeable...so far we've only spent two nights on the oat...I suppose we'll get used to it...

Filled in my chines. My glass and paint guy did a great job. Removed the gelcoat to glass and then filled the void with Coosa board and Westsystem with fiber fill. Then 2 layers of biaxal cloth with Westsystem. Finally gelcoat and fairing, ready for barrier coat and paint.

Not a great pic, but you can only tell it where there it red fairing compound.



Ted

O C Diver said:

Filled in my chines. Ted

Click to expand...

Yeah, I guess you really won't be needing those chines anymore with the new "trawler power", not that they did much good with the original power-train. I still haven't seen a wake to beat yours under full throttle!!

healhustler said:

Yeah, I guess you really won't be needing those chines anymore with the new "trawler power", not that they did much good with the original power-train. I still haven't seen a wake to beat yours under full throttle!!

Click to expand...

Yes, 9 knots @ 22 GPH in that boat is going to produce a sizeable wake. From what I have read, if she could have gotten over her bow wave 14 to 17 knots would be her planing speed. Maybe with some really big trim tabs. With 107 HP now, it's the slow lane for me.

Ted

Bacchus,

The process included gridding off gelcoat, bonding in CoreCell foam panels, covered with 2 layers of carbon tape and epoxy resin. The details are described and pictured on the NENTOA.org webstite. Drill down into Great Ideas, "Eliminating Hull Slap". The trick is to determine how much of the chine needs to be filled in, based on your specific hull design.

Puffin,
Thanks - nice write up and pics. Now on my long list of projects to consider.

There are treatments that can be applied to the inside of the hull in the forward "splash zone" that will reduce chine slap. Damping products applied above and below the waterline from the bow or crash bulkhead aft to the first bulkhead will reduce the transmission of chine slap. This works all hulls except cored fiberglass, because the core acts as a kind of de-coupler between the inner and outer "skin."

The previous owner of our Nordic Tug 42 applied teak ceiling to the hull in the forward stateroom, and it seems to have significantly dampened the chine slap sound. At least it doesn't seem bothersome.

I didn't mention that the first thing I did was to install 4" of sound deadening foam panels along the inside of the hull, under the forward cabin berth. Softened the slap but did not eliminate it.

My cold molded hull is really noisy. I aways heard that the wood coring damps noise, but mine seems to just ring like a bell. Can't make a direct comparison though, maybe if solid glass it would be even worse. I have not tried any interior treatments, just sorta got used to it.

meridian said:

Saw a trawler in the mooring field here. This is how he gets rid of wave slapping on the bow. Just a write-up, nothing for sale.
Prevent Wave Clacking FREE | Stop chine noise/clacking/slapping from waves on your boat

Click to expand...

Anyone else stumbling across this, the link can be found on the Archive:

Prevent Wave Clacking FREE | Stop chine noise/clacking/slapping from waves on your boat

Basically, it's just a couple of noodle floats strung on a line and tucked under the bow chines. I did something like that for our old boat (having never seen the above link) and it worked reasonably well.

I can't believe you guys are robbing your boats of chine slap. I thought y'all knew it was the boat's way of showing grumpy old water who's boss.


I've seen some people string a poly tarp under and around the bow to stop the noise. Looked impressive in a redneck engineering sort of way.


I think I'd go the pool noodle route first. Tie a little red plastic flag on the lines at the bow to remind me to remove them before I make a mess of the prop.

If I'm sure that the weather will be nice, I play out enough anchor rode to wrap around a stern cleat - forcing the stern to the wind. then sleep quietly in the v-berth,

I don’t even know ifwe get chine slap or not, we sleep in the aft cabin. Our guests sleep in the forward cabin and so far no one has complained.

LongJohn said:

If I'm sure that the weather will be nice, I play out enough anchor rode to wrap around a stern cleat - forcing the stern to the wind. then sleep quietly in the v-berth,

Click to expand...

I'll have to remember that when on anchor.

Comodave said:

I don’t even know ifwe get chine slap or not, we sleep in the aft cabin. Our guests sleep in the forward cabin and so far no one has complained.

Click to expand...

Does your boat have hard chines that rise out of the water at the bow? If not, it probably isn't an issue. Sleep well dear guests.

Comodave said:

Our guests sleep in the forward cabin and so far no one has complained.

Click to expand...

I'm reminded of the notion to not make guest accommodations "too comfortable", lest they want to stay longer...