Hull Number
It is stamped on the stern, upper right.see explanation from IC30A.com"According to my paper work the hull identification number is "CTYN0773M77L". What does that mean?" The hull numbering, as required by the USCG, contains 12 characters; 3 groups of four. The first four are manufacturer and size, i.e. CTY for Catalina Yachts and "N" for 30, "L' for 27, etc. The next four are the serial number of the boat (only the C22 exceeded the four spaces allowed with 16000 boats built-we dropped the "1" at the front). The last four are the year of manufacture and/or model year. This coding changed over the years.If your boat has the old number system. The first "M" means modified. The next two digits are the year built. The final "L" is the month "July" in the modified system. The later system started with an "A" which is Jan, "B" is Feb, etc. The second number is the year built (4=1994) and the last two numbers are the model year (95=1995)C30 # 049 was built in Woodland Hills in 1975. C30 #315 is a 1976. Your C30 #773 is a 1977 . As you can tell by the jumps in the numbers, Frank was cranking out a lot of C30's back then. Your members can e-mail me at catalina@catalina.net if they want to know what year, etc. their boat is.David Graas, Customer Service, Catalina Yachts