rocker stopper

Hi does anybody use this rocker stoppers from west marine ? They work ?
Davis 352 Rocker Stopper

We used them on our sailboat for 10 years and loved them. We stacked six of them about 10” apart with a 25 lb lead on the bottom to help with recovery. We did boom them out. Hard to beat for the price.

Larry M said:

We used them on our sailboat for 10 years and loved them. We stacked six of them about 10” apart with a 25 lb lead on the bottom to help with recovery. We did boom them out. Hard to beat for the price.

Click to expand...

Thank you , is good to know that they work, do you use 6 on each side or 3 and 3, and are you using wiskers (boom) on both sides?

Larry how long was your “boom”?
Got a pic of the boom and rig really handy?

rivierapaul said:

Thank you , is good to know that they work, do you use 6 on each side or 3 and 3, and are you using wiskers (boom) on both sides?

Click to expand...

Six on one side. The hats where maybe 6-8’ off the beam.

A sister ship of ours installed a Magma-Marine system and it gives it great reviews. Forespar also sells one that a lot of Norhavn’s had installed.

complete system

Roll Stabilizer / Flopper Stopper

Nomad Willy said:

Larry how long was your “boom”?
Got a pic of the boom and rig really handy?

Click to expand...

Sorry no pictures. With the boom, which was 20 plus feet long, the hats hung maybe 6-8’ off the beam. I used polypropylene line. I wanted stretch to smooth out the action. It was pretty remarkable how effective they were.

Anther quick fix if you have a mast and boom....

Hang your dingy off to one side and pull it up till light on the water.

Yes you will roll a bit in that direction, nearly the same as flopper stoppers, but the return roll gets shortened up significantly if your dingy weighs a couple hundred pounds or so.

Not roll elimination, just reduction.

Larry,
And that was probably 20’ from the gunnels. Hang my lunch box out that far and great results will be had. The illustration has them hanging on the gunnels.

We have a ss box like damper (for one side) that I’ve not used. Mostly because in Alaska most all anchorages are completely protected and there’s no need for roll reduction. Only one time that we had waves in an anchorage that I can recall. The tide came in and opened up the outer waters (Dixon Entrance) to the back of Very Inlet. Haha but we had the wind on the nose.
But now that we’re in Wash State we won’t be so lucky.

Eric: What I meant was 6-8’ from the gunnel (there’s a word I haven’t used for a while). lol

Funny, I knew what you meant....

OK Larry,
Mine is similar but haven’t felt the need yet.

Use the Magma stainless steel flopped stopper. Much more effective

Our boat tends to roll a lot at the dock and at anchor.
Tried the Davis Rocker Stoppers for the first time this year.
I was skeptical that the inexpensive Rocker Stoppers would have much effect.

We have no way to boom them out off the side. Only the possibility to hang them off midships cleats.
Hanging a stack of 4 off the side reduced our roll by about 40%. I am impressed. Plan to buy 2 more so we can try the Davis recommended configuration for our size boat: 3 on each side.

It's all about leverage and the further you can get the Rocker Stoppers out on a boom the better they will work. Obviously they would work best hung out on the end of regular trawler poles but even getting them out on davits as far out as you can will help considerably.

The biggest challenge I've had with the orange cones on my boat is getting them to sink fast enough. Even with more weight than recommended and a few relief holes in the cone part, they still don't quite drop fast enough on some rolls. So they're only really pulling for the second half of the upward roll on each side, not the whole time.

They take a little thought to get the most out of them. Booming them out helps, but there are other things that are just as effective. One of them is to take care with spreading them out. All similar devices (like the Magma stopper), create some flow as they pull the water towards the surface. The unit then has to drop back through that flow on the down stroke. After a few cycles, they create an uplift current stream, reducing their effectiveness. Even still, they are effective.

If the Rocker Stoppers are spaced as close together as shown on the packaging diagram, you can't get the full effect of each stopper. If they are pulling up through a 6" cycle (like just tied off from your gunnel), the uplift current created means that they should be spaced about 24" apart. Stringing 5 close together is probably less effective than 2 spaced further apart.

The other thing that really helps is modifying the Rocker Stoppers to help them drop. A couple extra holes in the "peak" of the hat helps them sink faster (as shown in the picture). I then added "reed valves" to help them drop even quicker. Because they dropped easily, that allows the use of a little 2# cannon ball as the weight (which then tucks into the hat for storage).

For a $50 investment, they are light weight, quickly deployed, quickly retrievable, stow easily in a 2.5 gal. bucket in the lazarrete, and therefore have many advantages over the Magma $tainless $teel $toppers. The Magma system might actually be 23x better, but fortunately I don't need that.

I used them - 4 or 6 on each side with a weight off my midship cleats (13.5' beam). They didn't work very well at all.

I have since pulled out the big guns and have one of these off each midship cleat https://www.flopstopper.com/FlopStopper/Home.html

Vastly more effective. This year I added poles & that helps even more (but more work to set up).

I'm going to fiberglass on "bilge keels" when I pull my boat out later this year or first thing in the spring. If those don't add enough stability then I'm going to add stabilizer poles when I replace my mast and boom so I can run "fish" when I'm running and "rocker stoppers" when I'm anchored.

I have been thinking about using something like the Davis rocker stoppers on my 27 Albin. I get a lot of roll from River traffic when I am on the mooring. The current runs by my boat at about 3 knots depending on the tide. Does anyone have experience using the Davis units in that kind of current? Guessing it may take additional weight to make them behave?

Would the pretension of the current help out at least on the first roll?

socalrider said:

I used them - 4 or 6 on each side with a weight off my midship cleats (13.5' beam). They didn't work very well at all.

I have since pulled out the big guns and have one of these off each midship cleat https://www.flopstopper.com/FlopStopper/Home.html

Vastly more effective. This year I added poles & that helps even more (but more work to set up).

Click to expand...

We recently got exactly that one. Got it from a guy who didn't need it, sort of as a favor since he needed to get it off his boat. Not sure we'll even use it . . . . We have paravane stabilizers, and just put the fish out if we need stabilization at anchor. These would work a lot better, as there is a lot more surface area, and it has the louvers as well, but not sure we'll ever use it.