Friday, June 3, 2011
On a recent calm day with negligible current, we zig-zagged back and forth across Onondaga Lake and collected data on electrical current draw and the boat's speed.
The horizontal (X) axis shows the amount of electrical current used in amps (48V). The vertical (Y) axis shows the boat's speed "across the lake bottom." When there are tides or currents, a boat's speed through the water can be quite different from its speed across the lake bottom. If the flow is powerful enough, a boat can be plowing through the water in one direction, but actually moving in the opposite direction. That's why we came DOWN the Mississippi River.
More data and analysis are at Bill's blog: http://cshare.psu.edu/projects/sunboat/Lists/Posts/Post.aspx?ID=10