On Fri, 02 Mar 2007 06:51:23 -0500, Bill wrote:

I have a 1996 Mariner 50hp 4 stroke motor. The prop has the following
numbers 48 827312A10 10.5P I believe the last set of numbers (10.5) is
the pitch. Is there anyway to tell what the diameter is with these
numbers?

These are the props listed for a 1996 Mariner 50 hp 4 stroke.

DIA P

10-3/4 x 12
10-1/2 x 13
10-3/8 x 14
10-1/8 x 15

Just guessing, but it might not be an original. :)

Measure the diameter it probably the second best way to determine the
diameter.

The best is to just call a dealer and ask.