Here is some information that may be helpful. My friend Phil in Oregon helped me with the selection of the clamp on meter and sorting out all the electrical questions I had.
Here is a little video on amp draw and a Minn Kota Trolling Motor. The T200 motors will most likely vary from this test due to the particular speed controller you use and other factors. It will only cost you around $38 to get some really revealing answers and have a really handy tool for general use around the house.
I did some on the water testing and with a NuCanoe Frontier 12 doing about 2 mph I only drew about 4 amps and at wide open throttle which is about 4 mph it drew about 27 amps. As you can see by these readings you will get a lot more run time out of your battery running at slower speeds. I was surprised how BIG the difference was between half speed and full speed.
If you are looking to get maximum range it might be a good idea to check and see what your amp draw is with your particular vessel and motor configuration at given speeds. Like I said my results were VERY SURPRISING to me.
Here is a link to e-bay where I purchased my AC/DC Amp meter. A very handy tool and only cost me about $38 shipped. Best tool I have bought in a while. Most of these meters will only read AC amps and are quite expensive. This one has 3 ranges for reading DC amps. 2A/20A/100A