Piers101

Hi people, I'm a long time modeller and back in the day gas RC (we're talking the 70s here). Anyway, I've gotten back into RC boating and I would like to use a water thruster/jet set up. My question is this; if converting from prop driven to waterjet driven but keeping the original brushless motor and esc, are there any other considerations I should look into for this conversion? I guess I'm asking do you need a higher rpm for the impeller than you would for a propeller, everything else being held constant?

Any info would be helpful, thank you .
Piers101