To Use and How to use, those are the questions (Published Winter 2009)
Another mid-Atlantic dawn was still a few hours away as we raced from Quebec, Canada, to St. Malo, France. The wind had built overnight, and forecasts for the day ahead implied more of the same. We had already broken both of our cast aluminum hydrofoils on the amas, contributing to unusually high loads on the rest of the trimaran’s structure. Suddenly, the unthinkable happened with a loud crash: the centerboard self-destructed up inside of the centerboard trunk in the watertight forepeak. Our 5,000-pound, ultra-light, 60-foot tri-foiler quickly took on water, half-filled the forward section of the boat and suddenly weighed an extra 3,000 pounds! The day was off to a bad start.
Daggerboards and their cousins, centerboards, are stout pieces of equipment, designed to resist the lateral forces of wind and waves and provide some directional stability to many multihulls. You’ll often find the retractable and adjustable daggerboards in each of the hulls of a catamaran in various up or down positions. Similarly, you may find a retractable centerboard near and perhaps forward of the mast. They seldom break and never easily. In brief, they offer some bite for the boat, against which the wind helps to propel the boat forward while reducing the amount of sideways slippage or leeway. There are both good and bad ways to utilize them.
Years after our attempted trip to St. Malo, I was aboard a newly purchased Atlantic 42 catamaran. We were going out for our first spin around the Bay in the boat. With sails up and close reaching in 10 to 15 knots of wind, we were barely moving. It was becoming frustrating, as I looked around to determine the problem. Within a few minutes I realized that we had forgotten to put the leeward daggerboard down. Once it was all the way down, we began to pick up speed. Without the resistance to the wind, the boat had little incentive to do anything other than slowly move sideways. Of course, hull shapes can also influence directional stability and the boat’s ability to translate the wind’s energy into forward motion, so each boat is almost unique in the way its daggerboards need or don’t need to be utilized. But in general, you’ll find that in moderate winds, putting the boards down is like putting your boat in gear. And if you’re looking for fast forward, your leeward daggerboard will almost certainly be down and you may even have both boards on the catamaran down to add to the lateral resistance.
THE UPS AND DOWNS
Since those early days of dealing with offshore multihulls, I’ve spent quite a few fabulous days, weeks and months sailing Gunboat high-performance cruising cats. Their light weight and generous sail area provide for exhilarating speeds, so you can quickly get to wherever you’re going in style. In a performance cruiser like a Gunboat, getting the most out of the boat means effective use of the daggerboards. Peter Johnstone, Gunboat’s owner, even provides each new boat owner with a detailed list of daggerboard settings and sail selections for various wind speeds and wind angles. Other multihulls may require a variation on that theme, but generally speaking, it’s a good place to begin as you search for your own optimized settings.
As with most things, there are issues and tricks you’ll want to know in order to improve performance and avoid problems. Most daggerboards are adjustable, and lines bent over sheaves and run through the board itself often control their adjustment. One line is the “up” line and the other is the “down” line. Having different colored lines for each task will help to eliminate confusion. Putting a mark on the line and numbers under the line along the deck will help you to quantify how much board is actually down and in the water. In various wind conditions you will want more or less board down, and you will want to know quickly and accurately how much of the board is down.
Often the up and down lines are run through a jammer. You may need to release the jammer for one line to use the other without breaking the line under load. Don’t overload the lines even when both jammers are open. The daggerboard is usually designed to slide up and down within a daggerboard trunk. When underway, the loads on the boards will push the board against the sides or aft part of the trunk, creating friction and inhibiting the up or down movement of the board. When trying to raise the board while underway, apply a modest load to the up line while the down line is released from the jammer. Allow the motion of the boat to move the board in the direction of the loaded line. The board should not be forced up by overloading the line. And, as with all lines, watch for chafe.
TRICKS OF THE TRADE
Heavy weather and big seas put large loads on daggerboards and centerboards. As winds increase, especially when beam or close reaching, you will need to pull the board up, at least partially. In the past, I used to always sail with the leeward board in the down position. In light to moderate conditions I would have more board down, and as the winds increased, I would pull the board up, reducing the lateral loading and reducing the likelihood of equipment failure. In talking with Peter Johnstone over the years, however, I’ve come to the conclusion that during heavy weather, it is better to have the weather board down and the leeward board up. If you are close or broad reaching in strong conditions and an approaching wave breaks against the weather hull, it would be better to slide sideways down that wave with no leeward board in the water to “trip” the cat. If the weather hull comes out of the water—an unlikely event on most cruising catamarans—the weather daggerboard also becomes less exposed to the water, allowing for more leeway and less likelihood of “tripping” on the board. In heavy weather you will probably want to have considerably less board down than you do in moderate conditions.
In light conditions, the daggerboard is often under relatively little consistent load. The board can tend to bang around inside of the trunk, leading to a lot of needless noise in the living area. One trick that I’ve found useful to stop the banging is to make a couple of wedges out of hard, smooth, relatively non-absorbent wood or Delrin. Drill a hole through the wide end of the wedge and tie a line through the hole, allowing enough length for the line to be tied off on deck with the other end of the line when the board is all the way down. When the board is in the desired position, dangle the wedge down the daggerboard trunk, with the pointed end down and allowing the wedge to seat itself between the board and the side of the trunk. Be careful not to raise the board with the wedge in place or otherwise jam the wedge too hard between the board and the trunk. You will have to remove the wedge whenever you raise the board, but at least the board will stop banging around and making noise in the light conditions.
The effective use of daggerboards can greatly help your multihull sailing and overall enjoyment. Pull them up, and amble into a three-foot shallow for a summer afternoon wade in the water. Put them down and blast off onto a screaming beam reach in 15 knots of wind. And use them to increase your safety as well as your fun. Enjoy!