"One thing though - a more powerful motor won't necessarily make you go any faster. None of these motors is the least bit taxed pushing something as light as our kayaks - they were designed with very shallow pitch props for pushing boats that weigh many hundreds, even thousands, of pounds. So, a bigger motor turning the prop at the same speed as the smaller motor gains you nothing. You just burn up your battery more quickly."
Tom...I wish I'd known that before I bought my Motorguide Varimax T55. Oh well...After reading this thread, I called my trolling motor guru to find out if he knew of any props built for speed. He said there were a couple companies out there that made performance props, but only 1-2 mph over 5 mph. BTW...Torquedo was one of the 2 companies, and a couple days ago I saw a clip of a guy testing his Torquedo using his GPS for reference and his GPS calculated his speed at 6.3 mph...Anyway, after talking to my guru, he gave me a number to an engineer that designs props for commercial vessels. The engineer told me that the issue with designing a prop with more pitch for speed for a small vessel would be the additional battery power needed, which would take up more space and also weigh much more. A 12 volt battery would not be enough to last very long. You'd need 24 or 36 volts minimum.
Sooo...What do you do. The hull speed for the PA is only about 7mph anyway, right? So it wouldn't do any good to try to get something that would get you over 7 MPH, which only leaves 2 mph max above the 5 MPH prop you'd want to get. So...If you want to go over 5 mph you either find a high performance prop and spend alot of money, and extra on batteries and live with the additional weight, OR...You just buy a small outboard gas motor.
I've got to admit that I'm a little disapointed because the reason for me going through the trouble of building a transom and getting a larger trolling motor was to be able to fight strong 4-6mph currents around the Chesapeake Bay Bridge Tunnel in Virginia where I live. All it took was one time being sucked under a bridge and out toward the ocean miles from shore, not being able to peddle fast enough to fight the current, for me to make the decision to get a motor. Unfortunately for me, now I believe I should have invested in a gas powered motor rather than electric.
Anyone have any suggestions? My current battery and T55 motor weigh 85 pounds. The battery alone weighs 65 pounds. I really don't want to add another 130 pounds for 2 more batteries, even if I could find a high performance prop...Or maybe I just live with what I have now with 5 mph