i have an old beetle motor that needs to be rebuilt, and I just got a small fishing boat (about 12 ft.). The boat has a 15 h.p. motor that needs to be worked on so I was wondering if it would be possible to use the VW motor on the boat. any comments or if anyone could knew where I could find info. on this I would greatly appreciate it.

VW engines have been used for boat propulsion with minimal success. In 1960 the "Volks-liner" was introduced. It was a 17' wooden boat, powered by a 36 HP VW air-cooled engine. Not too many of them were made. To see some pictures of one, go here:

http://www.edu-television.com/gallery/album21/aac

However, mounting one in a 12 foot fishing boat, which I presume has an outboard, would not be a project I would recommend.

You'd have to reinforce the hull, install stringers, remote throttle and steering. Install a rudder assembly, strut for the prop. Shaft log (the opening through the hull for the shaft) devise a transmission/reduction gear to reduce engine to shaft RPM, or redirect the shaft rotation (V-drive)

Add to that, the increase in static weight would make the boat unstable and probably unsafe. There's a reason that naval engineers design boat hulls for the desired propulsion system. To keep them above the surface with the correct side facing the sky.

You could probably do it if it was enclosed by something waterproof, Good luck with that .