Some of the books I have read, written by winning Hobie sailors, state that the tension is not critical. One of these Hobie experts states he has sailed with the battens untensioned and could not tell the difference. I have also had that experience, though my reasons for not telling the difference are probably not the same as that experienced sailor.
I usually set mine with enough tension to take out some, but not all of the wrinkles in the sail. Since I do this every time before sailing, I am sure that I am not repeatable. And the reason I do this is I untension the battens when storing the sails, which minimizes the stretching of the sail.
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Ted
Hobie 16
South Carolina Lake sailing
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