Thinking about ballast

[neilm]

I've been using sandbags for ballast when sailing my CLC Skerry which seems to work well but I'm wondering what happens if the boat get's knocked down? Will the bags fall out (possibly on top of me) or will it just fill with water and stay upright? Should I have secured ballast?

Neil

[paladin]

Secured ballast am always more better.....knew a feller in the Philippines that had bags of metal scrap and sand in the bottom of his 22 footer.....sailed down to Mindenao one weekend, they fished him out and brought him to Peter Paul candy companies coconut plant on suthrin' Luzon...I flew down to get him.....boat was extremely stable with the ballast stuck in the overhead and the mast pointing down....water was also considerably warmer than where you are......probably more sharks at his location.

[Peerie Maa]

I'm not familiar with the design. Is it an open boat?
The Norwegians and other open boat users would use round cobbles and small boulders, that would roll out in case of capsize. The boat would then float on the woods buoyancy, but not always upright.

[TerryLL]

There are a couple of bad outcomes with unsecured ballast. The ballast may shift during a partial knock-down, resulting in a full knock-down, or the ballast may be lost if the boat goes full over.

Looking at the CLC catalog I see the skerry has sealed air tanks for flotation, so sinking the boat shouldn't be a worry as long as the ballast isn't excessive. I think I'd want some straps to hold the bags in place, perhaps with plastic buckles for quick removal.

[johngsandusky]

Secure is better. But the Skerry is a 15' open boat. How much do the sandbags weigh? In my dory I have a couple of shotbags and a couple of concrete weights. They rest below the floorboards. Most small boats don't roll completey over in a capsize. They knock down until the rail is under, then stabilize as they fill. Wooden ones then float on their side, the mast is bouyant. If yours has bouyancy tanks, she'll float higher. Your bags would slide down to the lee side, but probably not fall out. You could throw them out if you needed. You also float. Don't worry about it.

[Thorne]

An interesting question. I've always gone for non-secured ballast in small open sailboats on the theory that I want it to fall out during a full inversion (like rolling in surf or heavy wakes). John is correct that most other cases are tilt -> partially fill over gunwale -> back upright -- so as long as your unsecured ballast stays put during a partial roll, you'd be fine.

For quick and dirty ballast I'll use a collapsible plastic waterjug full of water. This is handy as it can easily be moved, filled or emptied as desired.

For more professional (and space efficient) I have lead sheets covered with ducttape that fit under the floorboards -- which are not held down by toggles, so they'd float off and let the lead out during an inversion.

[johnw]

One nice thing about water ballast is that it's neutral buoyancy after the capsize.

[johngsandusky]

I used water ballast with my canoe. I was amazed at the difference two one gallon bottles made. In the dory I wanted more weight lower, I may add some still.

[Woxbox]

I put a 5-gallon jug of water up forward when I'm alone in my Whisp as trimming ballast. There's enough air in the jug that it won't sink if I ever turn the boat over. No built-in flotation, but nothing to sink the boat, either. But beyond trimming a light, open boat, why add ballast? That's normally accomplished with body weight.

[johngsandusky]

I found that the canoe, a double paddle design, was too tender. I had to be really quick to keep her up. The ballast helped. The dory too, in spite of her size, is very light weight. 40 lbs in the bottom helps a lot, she's not so quick in motion.

[Ray Frechette Jr]

I put a 5-gallon jug of water up forward when I'm alone in my Whisp as trimming ballast. There's enough air in the jug that it won't sink if I ever turn the boat over. No built-in flotation, but nothing to sink the boat, either. But beyond trimming a light, open boat, why add ballast? That's normally accomplished with body weight.

Too immerse a boat down to her lines.

If building a legacy design in modern glued lap the scantlings will be much less for same strength.

One fo the reasons scantling need to be more on traditional builds is that fasteners are only able to transfer around 25% of the strength of the wood. As such scantlinsgs need to be greater for same ultimate strength.

Glued lap is more of a monocoque construction method and much gretaer strength transmission.

Since the scantlings are lower much less of the boat is immersed in the water which makes it act tiddly.

Vertical center of gravity is all off. Also consider that the average girth and heft of most Americans is far greater than it was when the lines were drawn for several designs in the 1800's and early 1900's.

A bit more weight down low than the original hull would have had pays dividends in that regard as well.

[James McMullen]

Good points, Ray. I'd also add that some of those traditional designs were designed to hold a buncha codfish or something, much more weight than the picnic lunch or camping gear that modern recreational boaters carry with them. A modern adaptation of a legacy design ought to account for a generally lighter payload.

[Ray Frechette Jr]

Absolutely. One of my favorite quotes from Captains Courageuos original film adaptation is when Manual answers Harvey about won't he be lonely out there fishing all by himself. "no , Manual not be lonley. Very soon Manual have 50, 100 fish keep me company."

All that fish in the bottom of the boat added loads of Ballast. And it was oall nearly neutrally bouyant ballast too, and not fixed to the boat.

[TerryLL]

All that fish in the bottom of the boat added loads of Ballast. And it was oall nearly neutrally bouyant ballast too, and not fixed to the boat.


I've known or heard of more than a few boats that have rolled on their sides and slowly sank when all those unsecured neutrally buoyant fish have shifted to one side. Broken bin boards in the hold are the most common cause. Of course, I'm talking larger boats than Neil's Skerry. West Coast trollers typically load the hold with flake ice, in bins, when setting out, then use the ice to pack in the catch. But keeping the weight in the hold secured in place at all times.