# Need some input on boat propulsion

Can someone help me out with some ballpark calculation of propulsion power needed to move a boat?

I do have some specific questions:

1. Propeller vs. Jet: Which one will deliver more propulsion given the same amount of power.

2. If it is typical electrical trolling motor type propeller, is there some simple formula to represent relationship of boat speed, power needed (hp), propeller rotation speed, and diameter of the propeller?

3. If it is a jet: Is there a simple formula to represent relationship of boat speed, power needed (hp), boat speed, and GPF of water to move the boat.

I know that I am missing a few variables here like boat's weight and its water displacement. I am trying to keep it simple.

Any thoughts and input will be highly appreciated.

Thanks.

## Discussions

Power boat calculator here http://www.psychosnail.com/boatspeedcalculator.aspx