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
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
4) Attach a steel tape measure to same location.
5) Haul up the tape to the specified luff length you are
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
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