Hi David, hi all.
Be careful to look at the thrust value. Is important value but in our case is not the only one to look at.
with some approximation, the thrust value is SIMILAR to the torque value of a bike/car: high torque doesn’t mean high speed (think about the tractor).
The motors that you consider have high thrust, but they have the max speed pretty similar in the case you mount it on a 4m boat or if you put it on a kayak (or a surfboard).
this because they are born for this reason, garantee a max speed almost identical for different use.
(if you put a truck engine on a sport car that weight 1/200 without change gear, wheel ecc ecc, the torque and the max speed will be the same…)
But if you change the prop on this motor probably the thinks can change…