It almost always is an option. In most cases the engine has to be lifted to
get the pipe that routes down to the lower unit installed. There are filler
plates to cover where the thru hull tips are removed. Except for lifting
the engine it is simple work. You might look at slip in mufflers but they
will still be a lot louder than thru prop.

"*JimH*" wrote in message
...
We are looking at a nice 21 footer to use for water skiing, tubing and
general use on Lake Erie. The problem is that it has thru hull exhaust.

Is it easy to convert to an below the water exhaust (through the prop on
the I/O)? How much money in materials would be involved? Is it a do it
yourself project?