Slappy arse awb's

[steve yates]

Twice in the past I have been tied to a wall behind a big white med style boat with wide flat stern, with a bit of a swell rolling in astern giving a bit of an undulating night.
The slap slap slap noise from the boat in front was intensely irritating, and I made a mental note never to subject myself to a boat that made a racket like that when moored.

Is it only boats with swim platforms that do this? Is it ALL boats with swim platforms that do this? When we come to swap up from our Longbow, I want to ensure we dont get such a vessel, are there any particular models that re known for this or ones to avoid if I find this annoying?

I cant even remeber the boats in question exfpet they were modern and white, one may have been a jeanneau I think but could just have easily been a bene or a bav, so I dont want to damn one particular marque

And before anyone points out why awbs are better than mabs, I dont care, its not about that. We will want a stern cabin and I really really don't want that slapping noise under my head at night, its unrelenting. That would actually take precedence over any other factor in choosing

 

[pvb]

It's not just "slappy arse AWBs", more traditional boats can experience similar noise in certain conditions. My old Hallberg-Rassy was a bit noisy sometimes.

 

[steve yates]

Ok, but what and why? My boat was as quiet as a mouse, the other was making a horrible racket. I get that boats will make noises, but this was quite a specific effect, both times, bit of a swell and a loud and regular, slap, slap, slap, either as the stern dropped back down or the wave reached up to it. So what do I look for to avoid boats that do that?

 

[johnalison]

If it's any consolation, it will be much worse in the boat concerned. Our HR 34 has a fairly moderate stern and doesn't usually suffer but can do if there is much of a slop from astern. A friend's Bav 34 from 2002 didn't look much different but suffered quite badly, and many newer boats much more, of course. Any surface that is close to being horizontal can cause noise. Sleeping in the forecabin helps.

 

[Bobc]

It's the big flat fat-arses that cause it. That's why most of them have the master cabin in the bows these days.

 

[dom]

A bit of wave slap on the stern doesn't bother me in the slightest.

People pay a lot of money to hear the sound of the sea from their bedroom window!

 

[geem]

Its a function of flat hull sections in the stern area and the desire to lengthen the water line. I have not seen a modern hull shape that doesnt have these tendencies.
We were having dinner at anchor on a friends Jen 52 when a boat must have gone past and created a slight wake. The noise of impact of the wave on the stern felt like the passing boat had hit us! I couldn't believe it. The owner said it was very irritating and the reason why they slept in the bow.
I also couldn't live with that.

 

[mjcoon]

I believe there are mats, a bit like coir doormats, that are meant to turn the slap into a susurration. Dunno how effective they are or easy to fit under the counter. And you can hardly carry one to fit on an adjacent boat!

 

[ashtead]

We always slept in bow of our Bav34 and when buying new vessel also looked for one with a large bow cabin . The stern noise slap isn’t mentioned in reviews of Oysters though?

 

[MoodySabre]

My Moody 31 can get slappy and if it does then I tie a couple of fenders end on end and pull them under the stern, tied off on the pushpit. Job done.

 

[Moodysailor]

My Moody 31 can get slappy and if it does then I tie a couple of fenders end on end and pull them under the stern, tied off on the pushpit. Job done.

This is what i've seen done by a few in our marina, mostly by visiting yachts. I wouldn't want to leave fenders there all year round.

 

[doug748]

....


Is it only boats with swim platforms that do this? Is it ALL boats with swim platforms that do this? When we come to swap up from our Longbow, I want to ensure we dont get such a vessel, are there any particular models that re known for this or ones to avoid if I find this annoying?

......

I think they are fairly easy to spot. The worst I have seen are the fast cruising boats like RM, Django, Pogo; boats that are genuinely designed to plane as a priority.
Pure cruising boats with the transom flush with the water are also very susceptible in the slightest ripple. Where the transom is raised and there is some sort of V or U shape at the water, without a pronounced flat area, I think you do better.
You can see/hear it in the dead flat waters of a marina where there it passing traffic at 90deg to the run of the pontoons. Yon don't need an alarm clock when the anglers leave at 4.30h

.

 

[Achosenman]

Its a function of flat hull sections in the stern area and the desire to lengthen the water line. I have not seen a modern hull shape that doesnt have these tendencies.
We were having dinner at anchor on a friends Jen 52 when a boat must have gone past and created a slight wake. The noise of impact of the wave on the stern felt like the passing boat had hit us! I couldn't believe it. The owner said it was very irritating and the reason why they slept in the bow.
I also couldn't live with that.

I think you'll find for most of us, it's what the first mate can live with that counts...

 

[geem]

I think you'll find for most of us, it's what the first mate can live with that counts...

She sleeps through anything. Its me thats the light sleeper?

 

[KINGFISHER 8]

I once had the misfortune to spend the night on a clinker built Folkboat ... never, ever, buy a clinker built boat if you ever want to get a good night's sleep. An overindulgence of G & T didn't even help !!

 

[dankilb]

When we come to swap up from our Longbow, I want to ensure we dont get such a vessel, are there any particular models that re known for this or ones to avoid if I find this annoying?

You might be limiting yourself to a W36/Conway/etc. as there aren't that many aft cabin production boats without a slappy arse! Laurent Giles' Westerlies were quite unique in having a 'full displacement' arses, IMO!

The Hylas 44 we had back in the day wasn't slappy and had a massive aft cabin:

(not the actual photo - just off the interweb...)

But not that many aft-cabin boats with a stern design like this, these days. Think Hylas went to a sugar scoop too in the 1990s.

 

[rogerthebodger]

I found my boat had a slappy stern it I moored tern to the channel but when I moor stern to the mooring no slappy stern.

I also found the using a swimming noodle roped under the stern would stop the slappy noise

 

[ashtead]

Yes swimming noodles would be my first choice if I was that concerned if you have enough of them.

 

[Nimrod18]

I charter a HR34 once a year and have always been frustrated by the ill-timed slappy alarm clock in the aft cabin (not a euphemism). So thanks for the fender / noodle top tip.

 

[NPMR]

Our Jeanneau has this problem.

I cannot understand why the manufacturer does not spray the inside of the stern cavity with acoustic material when its being built. Simple, probably very cheap and a massive improvement on the night time racket! Not much weight either I would guess.

A profit project for an enterprising bod with the right kit?