Mainsail Leech Measurement Check

If your sail has a dodger or Bimini to clear you must provide the leech measurement.

A Normal boom is level (parallel to the water line or even with a fluid level).  Be sure that a level boom clears the Dodger or Bimini easily. If it does not, check the leech measurement as below.




To check a mainsail leech measurement, use the below procedure. (10 minutes)

1) Block the mast into the position you want it while sailing.

2) Mark on the mast the foot length you are ordering.

3) Attach a strong downhaul line to the main halyard (like a genoa sheet).

4) Attach a steel tape measure to same location.

5) Haul up the tape to the specified luff length you are ordering.

6) Swing the tape out to your mainsail foot length.

7) The resulting measurement is your leech length for the mainsail with the boom in the position you wish.

8) See all pictures below.

The leech measurement is always a straight line as indicated below. If you have a cockpit Structure to clear you must provide the leech measurement

Below customer failed to mention the Bimini or check the leech measurement.







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