Many years ago I was visiting a friend at his lake front house. He had a large, very heavy rowboat with no rudder (of course) but it had a trolling motor with a six-inch propeller. You could hurt yourself rowing that boat and the trolling motor strained to even get it to move. He told me the boat with oars and trolling motor weighed 1,800 pounds. It was wide and wallowed around in the water. The rowboat had come with the house and since my friend seldom had time to go fishing he had delayed buying another boat. He was going to be retiring in the next year and we were cleaning the house and sheds of the old owner’s things. I found a dozen new 6-inch, 12-volt, caged, dual speed, truck cooling fans.
They had stationary or oscillating switches and 2 big 5-amp solar panels. I asked my friend what would happen if we mounted the solar panels on a 4-foot x 8-foot sheet of plywood and mounted 4 of the fans to the plywood. The 2 outside fans and plywood would hang over the sides of the rowboat. There were a couple of 12-volt automobile batteries sitting in the shed. We could set the batteries under the plywood; connect the solar panels and fans to the batteries. My friend gave me a sideways, wide-eyed, panicked look. But being an intelligent man, he shuddered, gave in, and said. “Anything you want to try is fine with me.” It took several hours but we got everything mounted on the boat. I tied the plywood to the middle and the front seat two seats with rope, telling my friend. “I do not want the fans to act like helicopters and take off with the panels and plywood.” My acquaintance gasped, sputtered, and finally howled with laughter. The trolling motor acted as the rudder for the boat, if the motor was running.
I did not think the six-inch propeller, with the motor off, would make a very good rudder. So I tied and taped a small nylon bag around the propeller. My acquaintance stopped laughing and started to look nervous. “Careful, we have to take that off to get back here.” I glared at this near stranger and muttered about…lack of faith…none of my experiments have actually failed…true some turned out differently than I thought they would. I was not in a real good mood when I used an oar to push us away from the dock. The oar got stuck and I almost fell into the water. The stranger sitting beside me was howling with laughter again. But when I reminded him we now had only one oar he stopped laughing and started to look like he was going to cry. We were moving a tiny amount from my push. I reached forward and flipped the four fan switches to low speed. We were moving! Well, at least we were not slowing down. For a few minutes my friend and I watched the water moving past us. “Faster! We are moving faster!” He screamed into my ear. batteries for a fishing boat
It took about four minutes for the boat to get up to full low fan speed. We went around and up and down the lake several times. To the best of our calculations we were doing almost 6 miles an hour. We went back to the house and hooked up a battery charger to the batteries. The next morning we repeated the experiment one more time, and then when we were up to full low fan speed we switched to high speed on all four fans. We calculated we were doing 13 miles per hour! Even with the solar panels the batteries were drained in two hours. We used the oars the last 30-foot, to make it back to my friend’s dock. We drove into town and my friend purchased the fiberglass fishing boat, it even had a little cabin, and motor of his dreams. That boat, motor, all of our stuff and we only weighed 1,400 pounds total. It was slightly longer, a lot narrower and rode higher in the water than the rowboat. The next morning we padded the new boat to protect it’s surface from scratches from the plywood. Then we were off! When we finally reached full low fan speed we calculated we were traveling almost 11 miles an hour. Finally my friend flipped the fan switches to high speed. To the best of our calculations, with no other boats on the water to cause turbulence, we reached and maintained 34 miles per hour.