Roll, roll, roll your boat…

September 19, 2016 by s/v sionna 8 Comments

We love our boat. She’s strong, capable, amazingly roomy for her 32 feet, well built and well equipped. Sionna is the perfect boat for us. But she does have one vice.

She likes to roll.
Any time the wake of a boat or a sea comes along at anything close to broadside to our old fat boat, she sets up a motion that’s like riding a round-barreled pony who’s determined to roll in the grass. Baaack and forth, Baaack and forth…. Every boat around us is gently riding to the swell, and Sionna is tossing dishes across the cabin while Nicki and I hold on for dear life. And sleeping? I don’t think so.

Hence my latest project – creating a “flopper stopper” – a device to catch hold of the water next to the hull and use its weight to reduce and dampen the roll.

The idea isn’t new, and it isn’t original. I’ve read several articles over the years about various designs, and a couple of fellow cruisers have shared ideas as well. The one I made is based pretty closely on a recent article in “Good Old Boat” magazine, so here’s a shoutout to a truly excellent publication!  

Materials are all found items: An old milk crate Nicki’s had since childhood is the base, the fabric is an old sail from the boat we didn’t restore (thank you Renaissance!) the weight was in Sionna’s bilge when we got her, and the line and clips were repurposed from various corners of the boat.

Once deployed, the flopper-stopper is below the waters surface, but it acts like a weighted bucket with a one-way valve in the bottom. Water can come up into the bottom easily, but is slowed significantly in escaping, using the weight of the water to slow the roll of the boat side-to-side.

The horizontal pole just holds the unit at a distance from the hull, creating leverage, and the two lower lines keep the whole works out perpendicular to the hull. The support is a halyard from the top of the mast.

Does it work? Certainly it helps, but there hasn’t been a huge amount of wake or swell this afternoon to test it. Mostly we seem to be riding up and down on the swells, with only a little roll thrown in.

 Cautious optimism reigns until proven unfounded!