Sail Area

[Dan Dickison]

I'm finishing a wooden dinghy that I found abandoned. I would like to know whether there is a formula to determine how much sail area this boat requires?

Dan Dickison responds:

Thanks for the question. Sounds like you've got an interesting project. How much sail area your boat will require depends on a number of factors. If the boat is a simple sailing dinghy that is also equipped to row and tow, then chances are you don't want to add too much sail area because the inherent structure of the boat wasn't engineered for the kinds of loads that a mast and a lot of sail will develop. If the boat is a racing dinghy, then you'd probably be OK adding a fair bit of sail area.

Here's what you do: check out some boats that are similar in design, size, and weight. (You can do this by way of several publications like Sailing World and Cruising World's annual resource issue.) Find out what the designed sail area is for those boats, and then adapt that for your boat. If you're planning to pay a sailmaker to build the sails for you, you can always engage that person to help you with the research. I'd suggest contacting the good folks at AirForce Sails and asking them if they can assist you. Here's hoping this information helps you get started.