converting Newtons to kW

I've seen a couple of formula's and programs that give the drag of a hull in newtons (or kN). Can someone tell me how to convert this to the amount of power required to push the boat?
(I know it depends of prop efficiency... between say 55 and 70% for normal ones, depending on set up)
Is it simply that one kN drag requires one kW of thrust?

 

Power (watts) = Thrust (N) x Speed (m/s)

 

Ahhh - got it.... shoul've know I only had to go back to one of my high school physics books...
Thanks Raw

 

resistance times velocity gives power. That's EHP then there's the power train and efficiencies to consider , prop at 55% maybe 3% for friction on the shaft ,
required EHP is often taken to be around 35% of the engine flywheel rating.