Sgt911,
I took a look at that a while back. Seems I found a guy to do it that made boat houses on the local public lake for a living. For the amount of $ he was asking to drive the posts it would have cost a mint to build the pier. Luckily we hit a drought and I didnt have to worry about water.
Seems like if you had a stable boat, you could drive 4 inch (or so) drilling pipe yourself as long as you had a swamper or two to help out.
Can you drain the pond?