Flopper Stoppers?

[chouliha]

We have one that was home made 25 years ago and have used it many times. Spending 2 months out at Socorro island in Mexico we used one 24/7 to help with the roll. As soon as one of us says should we deploy the flopped stopper then it gets setup and deployed. It does work and Linda feels it immediately when I pull it out of the water as we are getting ready to get underway. Even if we are stopping only for one night if we feel we need it we throw it in.

Attach the line to the pole (other end attaches to flipper stopper), Run your spinnaker pole up as high as possible, set a fore and aft line to keep the pole in position and toss it overboard. With everything marked so you can preset it usually takes less than 5 minutes from start to deploy.

Safe sailing

Chuck
Jacaranda

[markpierce]

It's the joy of mooring. If it is annoying, you're in the wrong moorage.

[Jim Cate]

Originally Posted by markpierce

It's the joy of mooring. If it is annoying, you're in the wrong moorage.

That may be true in the friendly confines of SF Bay and environs, but in much of the world's cruising grounds there may be no other option than to stay in the rolly anchorage. It may well be tens, hundreds or even thousands of miles to a better spot!

In the case of the Socorros, it is hundreds...

Cheers,

Jim

[DeepFrz]

They are used on trawlers for addition stabilozation. The dampen reduce the roll. We may add them to the Eagle as its round soft chime. Trawler drop use them mostly when under way. Not just at anchor like a sail boat would.

Two different things. Completely different designs and used for different purposes. However many trawlers do use the "at anchor type flopper stoppers" as well as the fish when underway.

[HappyMdRSailor]

Originally Posted by rebel heart

They were fast on their way to reply to this thread but then they realized that 1/4 of their progress was to leeward.

Reb... I wasn't supposed to laugh at this..... Was I ???

[wsmurdoch]

Originally Posted by Mirror16

In the December issue of 'Cruising World' magazine, Cap'n Fatty Goodlander writes about his home-made "Flopper Stoppers" reducing the amound of rolling in a rough anchorage. He describes these as weighted plywood triangles suspended from two spinnaker booms, poled out on each side of the boat.

I've never heard of this, so can someone elaborate? Are the wooden triangles suspended horizontally? If so, how? Are they both continually submerged or only one at a time when the boat rolls to each side? These things must take up quite alot of space and would not seem to be useful for anything else. Wouldn't some other dangling arrangement (buckets? sailbags?) be better to dampen the roll? Any info appreciated. Thanks

I've not done it myself, but if you have a couple of milk crates on board for storing things, they can be dual purposed. Cut a square piece of conveyor belt rubber sheet, thin stiff plastic, or some such stuff to fit the bottom of each crate. Cut each square on both its diagonals to form four triangular pieces. Punch two holes in each triangle along the long side. Place four triangles in the bottom of each crate covering the bottom and tie them through the holes to the crates with 1/4" line or zip ties so they are hinged on the side and opening in the middle. Tie a weight to the bottom of the crate and a four part bridle to the top. Hang one underwater from the boom guyed out on one side of the boat and the other from the pole guyed out on the opposite side. The triangles open on the down stroke and close on the up stroke. The crates don't skittle off to the side on the up and down strokes like the corner weighted plywood triangles do.

[Dennis.G]

We have the Magna made large flopper stopper. Do not use it all the time, but when needed it makes a huge difference. Last time was anchored off of Cabo San Lucas. Wind came from North, swell came in at 90 degrees from the East. The flopper stopper did not stop us from rolling, but it reduced the angle of roll to about half that without, which is a big difference. Others in the anchorage got no sleep at all that night, but we were fairly comfortable and at least slept some. A very valuable anchoring tool in my opinion.

[RaymondR]

I have cruised the eastern and northern coasts of Australia continuously since 2002 and have suffered the rolly anchorage problem on numerous occasions.

I have tried many solutions and have found the best to be to just get used to the rolling. Some anchorages are so bad, generally because the tidal stream holds you beam on to the swell, that it is better to stay at sea and heave to.

I have never tried the roll stoppers but have had a number of discussions with other folks who have and their opinion was that if they are big enough to do any good they are a real nuisance to have aboard and that unless you hang a heavy weight on them to pull them down they tend to jerk.

I have tied a light line to the anchor rode close to the anchor, taken it to the stern and used it to slightly change the angle of attack to get the swell period out of step with the natural roll frequency of the boat but it requires a bit of tending as the tidal streams change.

A lot of the power boats in this part of the world have swing out side booms with fold up and extendable poles with fold up plates to dampen rolling when at anchor I don't know how effective these are.

I have pondered on the rolling problem, not just for anchoring but also for downwind sailing, and have concluded that a flume system using port and starboard water storage tanks and an electrically controlled butterfly style control valve might prove the most effective. The electronics to control the valve is cheap and readily available these days and a trial would not be that big a project.

Rolling is a resonance phenomenon and it does not require a large mass shift to damp out.