A lot! There is a difference between the old P2s and the new P2s too. The P3 is a deep hulled boat, rear fuel tanks, and longer 193″ compared to the 190″ P2. The P3s, at least mine (2003) has the recessed trolling motor tray. The deck layouts are different between the P2 and P3. On the older P3s, be mindful of engine selection. They perform better with 3 liter blocks. I have a 3.1L yammie, and it runs well. I love mine. I would be happy to answer any other questions. Good luck in the search! Bill