I'm guessing that 4.5" isn't enough, and 9" mightn't not be too much. I go by feel; load up the helm a bit any time the boat is heeled. You want to put that long, effective rudder to work reducing leeway. -----Original Message----- From: Les Schuldt Sent: Friday, May 03, 2019 2:23 PM To: montgomery_boats@mailman.xmission.com Subject: M_Boats: M17 Mast Rake I tracked down a calculator at: https://www.triangle-calculator.com/?what=rt&a=b%3D262+A%3D1&submit=Solve Input: b=255 A=1 This is the mast height 255 inches (21’ 3”) and rake angle of 1 degree The result is 4.451 inches. So if you float the boat on her lines and hoist a light line via main halyard with a weight tied to the bottom end (I use a crescent wrench), one degree of rake should leave the line about 4.5 inches from the after side of the mast near the base. If your mast is a different length, go to the website and plug in your numbers. Les