The measurement is from the bottom of the mast to the top edge of the bottom band and to the bottom edge of the top band. As follows:
Bottom of mast to the top edge of the bottom band: 2,698mm or 8.85 feet.
Top edge of the bottom band to bottom edge of the top band: 11,582 or 37.998 feet.
We do not measure these during inspection for the NA's but do check to see if they are in place.
Obviously, your bands should be white.
This information is available on the website under rules and specifications
Larry ChristyJ30 Class