How can I get my expensive 50v battery to work on a kayak?

I was thinking, since I got this 50v 20ah battery for my e-bike, why not get a motor to put on my kayak that can use the same battery? Is there any known trolling motor that can take 50v? Or has anyone made a motor set up to use on a kayak? If not, is it possible to get the voltage down a simple way usable on a kayak?

I'm trying to do the same thing for a trolling motor. On ebay there's a 48v to 12v 30amp converter. I'm pretty sure this would work but I have know idea what kind of range it would get. Let me know of you come up with somthing

will do

I'm trying to do the same thing. I have ordered the DC DC 48V to 12V 30Amp converter for my Minnekota EnduraMax 40. This motor will draw 42 amps maximum so could be too much power drain for the converter, on max throttle. I imagine my sweet spot for my canoe is around 250 watts, which would be 20 amps continuous, which the converter will handle supposedly. We shall see - just need to not max out the throttle! Its just for backup from my new sail rig.