It appears like the lower grommet has been used the most. The upper one is around 6 inches higher up and has seen little use. Is it to provide a flatter sail? I do not know if the sail is one that originally came with the. It is an O'day sail made by Neil Pryde.
My previous sailing experience has been with Kayaks and canoes using lug sails, so this has me stumped.
Also is it worthwhile adding oar locks and rowing a boat like this?
Thanks.