I use a 6' sickle mower. I was overly frugal at the time of purchase, and should have got an 8' or 9' (like Kyle suggests). What I forgot is that you'll want you tires to be 2 feet in from the edge of the dam when trimming the sides or the dam or the sides of the pond. So with some offset to the mower, I can cut about 4.5 feet of the edge. It's enough to keep things under control, but every year I have to clip some things back by hand.
Also, if I had bought a 8-9 foot cutter, I could run it vertically to keep the edges of the hay fields cut back. I can do that now, but, I miss a little at the top and a little at the bottom. You can see by the picture, two more feet would be great.
Like all purchase decisions, trading up would be very expensive so I'll live and learn, and cut by hand each year for as long as I can.
We added more dirt and made the back side (non water side) of one of our dams such that we could back up the dam to mow it.
I know the sickle is expensive, but it's a great tool and matches the 4x20 series very well. Used might save you some money. Good luck with finding your solution.
Pete
