The 1975 and earlier (1973-75) O'DAY 20 had a 22'9" mast length, 8'4" boom length. The stock sail area was 174 sqft. (Masthead rig)
The 1976-78 Oday 20 had a 27'0" mast length (approx. 31' off waterline) and a 9'6" boom. Sail area was 190 sqft. (Fractional rig)
The O'DAY 20 was a K/CB boat for the entire production run (1'2" cb-up, 3'11" cb-dn).