Get Beyond Your Guide
Get Beyond Your Guide
Progress from good to great by really understanding what makes your boat tick. "Boatspeed" from our April 2011 issue.
These basic settings are the starting points on the road to really setting up your boat with neutral helm. But what the best sailors know is that all boats,
even strictly controlled one-designs, are not exactly alike. With keelboats, especially, the realities of mounting the keel, deck, mast step, etc., can add up to some major differences in boatspeed influencing factors. Afer you’ve followed your sailmaker’s tuning guide to the letter to get to your basic setup, carefully quantify the differences that may exist between your boat and some sisterships. Refer to the diagram below for a handful of important measurement points.
The diagram addresses the major variables that can influence how easy your boat is to sail and therefore how fast it will be, on average, around the track. Before looking at these variables, check your class rules about the amount of tolerance in each. Many of them, like mast stiffness, are unregulated, and in most cases, there’s enough of an allowance to be able to gain a significant advantage by carefully looking at them and optimizing your particular boat. It will take time and experimentation, but I can assure that by optimizing each one of these, in total, you will have taken very significant step to making your boat faster. You can now put the cookbook away.
Where the Differences Lie
Not all one-designs are created equal. Here’s eight common areas where differences from boat to boat may be subtle, but ultimately important.
1. Overall mast length: Assuming the forestay length stays the same, the longer the mast the more vertical it becomes, which reduces rake and helm. A shorter mast would mean more rake and more helm.
2. Forestay length: A longer forestay adds rake to the sailplan and increases helm. Conversely, you’d shorten the forestay to decrease helm.
3. Spreader angle: Angle the spreaders forward to reduce the tendency of the mast to bend under load, and to increase helm. If you have a very stiff mast, angle the spreaders back to help induce bend and lighten the helm.
4. Stiffer or softer mast (measure deflection and compare to others): A stiffer mast usually allows the main to set up fuller, which increases helm. A softer mast usually is easier for light winds as it pre-bends more easily to flatten the main in lighter winds.
5. Fore-and-aft mast position at the partners (keel-stepped masts) A mast that’s chocked further aft at deck will increase helm. Chock or move the mast forward at the deck to decrease helm.
6. Fore-and-aft keel position: Having the center of effort behind the center of lateral resistance gives the boat helm. The closer these two points are, the more balanced the boat will be.
7. Full versus thin foil sections: While not directly affecting your helm, foil-section thickness has a direct effect on speed. Generally, a fuller section
is better for lumpy conditions, and a thinner section is better for flat water.
8. Vertical rudder angle: Angling back the bottom of the rudder back increases helm. Conversely, angling forward decreases helm.