New goal.....a 10K in the pool

Since I am spending so much time running/jogging in the pool, I think I am going to try to do a 10K in the pool.  First, I will need to find a pedometer that is water proof.  Once I figure out how many steps it will take to hit a mile I will be good to go.  Now I have to figure out a goal time.  Once I do a 10K, I will work on a half marathon.  I know this might sound foolish and like a ridiculous amount of time in the pool but I think it is an exciting challenge and one I can accomplish.  I have always envied people who could run marathons.  Well now I have found a way to do it myself. I am aware there will be no medals at the end but that's OK.  I may even invite some friends to stop by at various points to see how I am doing and to make the time go faster.  If I can find a water proof headset I'm ready.  I know the Olympics will never have a water marathon event but that shouldn't stop me from trying....should it?