After looking at the digital graph of speed and amps verse time, I really think there are limits to the single speed report of the gps units.
When running the boat in a straight line, you can see the speed climb up and the amps drop as the prop unloads. In choppy water, you can see the spikes of the amps as the prop hits and the speed is also very choppy. As an example, the speed will bounce around 34mph consistently on one of my boats, but the range of the bounce is 32 to 37. So the boat is running a consistent 34mph, but the peak speed registered is 37. But it is not a 37mph boat, it is a 34mph boat.
The hand held is helpful, but I feel limited. But it is also more afordable and usable for other things. The eagle tree is more expensive, but gives you a ton of data to look at if you want that. But you are limited on using it for anything else.
Depends on what you want and can afford. For me, the eagle tree was a clear winner and I am very glad I got mine.
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