(I call everyone kids since I turned 40 a couple of years ago, so don't take offense) Think about this, GPS is speed over ground, if you have a boat that goes 70mph and you are going down current on a river with a 10mph current, you ust got a extra 10mph thanks to the river. All you have to do is make sure you do your top speed run going down current and your cruise speed back "up" the river. That's why the Kilos are run in "both" directions. I would be more concerned with the "water" speed of the boat. I remember one time I was fishing 70 miles off of Jacksonville and we were trolling at 0 mph in one direction and 14 mph in the other on the GPS but if you looked at the Yamaha speedos, we were going 7 mph each way! Just thought I would throw this out there for ya'll to think about, GPS isn't the final answer in speed.