This link is from Ikes site that goes into some of the details of breaking down the code.

Pontoon hull identification number. Since November 1 1972 all boats must have a 12-character hull identification number HIN. If the number is on a separate plate. They are engraved in the fiberglass or on a metal plate permanently attached on or near the upper starboard right side of the transom.

It is an alphanumeric combination encoded by authorities with additional encryption for essential data security that links a vessel to its owner and manufacturer. The HULL Identification Number of a vessel is a 12-digit ID number. On catamarans and pontoon boats with hulls that are easily taken out and replaced the primary HIN code should be attached to the aft crossbeam within 1 foot of the starboard hull attachment.

On fiberglass boats they are molded right into the hull itself by the manufacturer. What are HULL Identification Numbers. Its there somewhere look on the engine pod or the aluminum frame that supports the POD check crossmembers on the right hand side on the stern would be the farthest one aft.

There is also an additional hidden secondary number located on the boats interior side just beneath the fitting. Specifically on pontoon boats the Hull Identification Number is on the stern side near the starboard hull attachment. This is often referred to as the boat serial number or boat ID number.

How to Identify Your Boat. It can also be placed under some hardware. Where do I look for the hull identification number.

Decoding a Pontoon HIN Identification Number. First youll need to locate the Hull HIN numbers which should be stamped into the metal on the back of the boat on the right facing the rear of the boat. The HIN may also include a 2-digit country code at the beginning of the boat serial number.