Tech Wiki

What is my boat's hull number? When was it manufactured?

You'll find your boat's hull identification number (HIN) inscribed on the upper starboard portion of the transom. On older C34s without the walk-though transom, it's also inscribed behind the removable Catalina plate over the stem hatch lid. In addition, you'll find the HIN on your boat's official documents (including insurance certificates).

Hull identification numbers contain the following information:


  • MMM = Manufacturer’s Identification Code
  • hhhhh = Hull Serial Number
  • dd = Date of Certification
  • yy = Model Year

For example "A4": The "A" stands for January, the "B" would stand for February, etc. The "4" stands for the last digit of the year of manufacture. (Reference: U.S. Coast Guard Auxiliary Boating Skills & Seamanship, 11th Edition, pages 2-2 and 2-3.)

A real-life example: Juliana's HIN is CTYP0680A888. Therefore, it's a boat manufactured by Catalina Yachts with the serial number P0680 (hull 680); the boat was manufactured in January, 1988, and is an '88 by model year.