Reducing centerboard knocking at anchor

[innervations]

Just spent 3 nights at Rottnest island (about 10nm off Perth, Western Australia) in our new Mac26M. Had a fantastic time and VERY comfortable but...

One night a bit of swell was coming into the bay, the wind was holding us side on, and we rock and rolled all night. I dropped the daggerboard in the middle of the night and that really dampened the rocking but we could not sleep for the knocking of the board in its cavity. So, up came the board and we put up with the rocking. Admiral not overly happy

Has anyone had success reducing the knocking of the daggerboard when at anchor? I thought of diving under the boat in the afternoon and placing some rubber chocks and remove them of course before hoisting anchor. Bit extreme though. Klaus, who is the MacGregor distributor in WA suggested lowering a rope down the cavity but I could not get this to work. Maybe too many beers before I attempted the accurate rope lowering feat

Anyone else come across this problem?
Cheers
Rob

[TAW02]

There is a device. I think it's called a 'rockerstopper'. Don't really know how well they work (never tried one), but I understand that they are also easy to build. Have seen them in various shapes and sizes.

Might search the knowledge base of this site or google 'rockerstopper' for more information.

[Chinook]

Centerboard clunking is something anyone with either an X or an M experiences sooner or later, while at anchor. Only solution I know of is to keep it up while anchored. As for reducing the rocking motion, some guys deploy a rocker stopper setup over the side. Something like a weighted 5 gallon bucket suspended from the boom. You can also try setting a stern anchor so that your bow is held facing the swell. The motion is not nearly so troublesome in that position.

[Trouts Dream]

I lower my rudders and this also helps without the knocking

[Wind Chime]

I've thought about doing this to stop the keel from knocking:

- tie a line to the base of the forward port stanchion.
- run the line outside all the rigging,
- around the bow and all the way around under the boat back to the port side.
- tie if off to the base of the rear port stanchion.
- tighten the line off, so it holds the keel to one side tight.

I haven't tried it yet, my only worry would that the line might get wedged in the keel and the trunk.

[Wind Chime]

I've thought about doing this to stop the keel from knocking:

- tie a line to the base of the forward port stanchion.
- run the line in the water, around the boat, outside all the rigging,
- once the line is around and under the boat, tie it off to the base of the rear port stanchion.
- tighten the line off, so it holds the keel to one side tight.

I haven't tried it yet, my only worry would that the line might get wedged in the keel and the trunk.

[David Mellon]

I use Davis Instruments Rocker Stoppers, I have a couple 6 pound mushroom anchors as weights. Originally I planned to build an outrigger system to get more effect, but, I got lazy and decided to just splice some loops at the top end and hook them on the winches. Be sure to use enough line so the top Stopper is below your hull. I find they work very well and, unlike my rudders and daggerboard, they are silent. I store them under the V berth on the port side with no problems. Be sure to haul them up before trying to motor away, they really have a lot of bite. I think they would be very effective as a storm anchor hanging off the bow.

[innervations]

Thanks everyone for the useful replies. I think I will give the rocker stoppers a go.
Cheers
Rob

[boatbitch]

Found the same issue chasing nightly sounds. I used a cheap oar from my inflatable dingy, I could jam it between the dagger and the well wall with the dagger half up. Also full ballast stops the sloshing sounds of the hull. And bunjii the rigging so it doesn't slap the mast is nice.

[Divecoz]

Speaking of........ How to be Rude Crude and Impolite and how to Embarrass fellow sailors in the Marina or P. O. everyone in an Overnight Anchorage!!!!
It takes but two light weight bungees to silence those lines! I have yet to see anyone actually cut anyone's lines.... but its been threatened and maybe well deserved to happen many a time at every Marina in the world everytime the wind kicks up ..
JSYK if you dont know how and there are no doubt other methods.. Hook a bungee on the inside shroud line then thru the lines at the mast and back to the outside shroud line, do this on both sides
Thanks for bringing that one up BB...!!

And bungee the rigging so it doesn't slap the mast is nice.

[Russ]

It takes but two light weight bungees to silence those lines! I have yet to see anyone actually cut anyone's lines.... but its been threatened and maybe well deserved to happen many a time at every Marina in the world everytime the wind kicks up ..
JSYK if you dont know how and there are no doubt other methods.. Hook a bungee on the inside shroud line then thru the lines at the mast and back to the outside shroud line, do this on both sides

Good point. There is no excuse for making our neighbors listen to our halyards clank in the wind, a common beef with sailboats.

You don't even need a bungie. Just wrap the halyards around the spreaders and tie them off tight.




--Russ

[kadet]

I epoxied about 30cm of electrical conduit to the top edge of the dagger board (I found it in the mods area to fix edge damage), added bonus is no more banging at anchor with board down as it fits tight in the trunk.

Regards
Kadet

[Boblee]

The rocker stoppers sound like a good idea but would think they would work better with a bridle as well.
Picture is of "trust me" after a wild night where the rocking got so bad due to being side on to the swell,I thought the mast and rigging would come down, the swell was now on the nose and the wind broadside.
So got up and set it up and it worked a treat, we were still pitching fairly bacly but thats not really as much a problem when trying to sleep as roling from one side of the rear bunk to the other, especially when another bloke is there no boy boy stuff on my boat.

[Divecoz]

Can you tell us why you were forced to let it broad side you all night? Boats at anchor, naturally desire to point, into the wind..
Rocker Stoppers work best, if supported several feet off the mid-section of your boat.. aka closer to the center board they are, the less effective they are ....I might Think if you had a length 1-1/2" Grey High Pressure plastic pipe ( Big Box Store ) slipped inside a 2" Grey High Pressure Plastic Pipe you could then extend them across the deck attach at the stanchions and the mast and still be several feet out from the hull. You'd have to play with the length of each to find the best fit...Cheap Easy to build and install and stow on deck against the stanchions when not in use. I stow a 10' (?) piece of 2" white PVC capped on both ends as a push pole when I am in Florida with the boat..

The rocker stoppers sound like a good idea but would think they would work better with a bridle as well.
Picture is of "trust me" after a wild night where the rocking got so bad due to being side on to the swell,I thought the mast and rigging would come down, the swell was now on the nose and the wind broadside.
So got up and set it up and it worked a treat, we were still pitching fairly bacly but thats not really as much a problem when trying to sleep as roling from one side of the rear bunk to the other, especially when another bloke is there no boy boy stuff on my boat.

[Boblee]

G'day Divecoz
Sorry just found I hadn't answered this, actually I tried and the computor shut down and hadn't got back.
The wind was coming from a similar direction to what it is in the photo but the swell which was fairly violent was coming onto the bow, we were in a sheltered inlet but a cat owner had told us it was not good (I knew better ).
When we anchored we had 8m of water but during the night due to swinging and tide we ended up with just over a metre, outside it was blowing over 25knots and a 4-5knot current from the 7m tides.
While we had shelter from the wind it was still strong enough to point the mac into it most of the time but by putting the bridle on it pointed it into the swell and stopped it dancing, we did have both anchors out at 90 deg which usually holds it reasonably steady but with the scope needed for 8m and the change of tide it allowed it to swing a fair bit.
Thankfully I had picked up on the use of a bridle here prior and along with many other tips it was invaluable especially in a tricky area like the Kimberlies, we had to anchor in dozens of different circumstances made much worse by the tides and narrow areas trying to get shelter.
Bob