List of factors - some minor, some major

- prop pitch
- prop diamter
- prop efficiency,
- Driveline efficiency
- Strut Depth
- hull Drag
- Hull Type
- motor efficiency
- Amount of Load placed on motor
- LiPo C rating
- LiPo Capacity
- LiPo Voltage Drop
- ESC/Wiring efficiency
- Water Conditions

and several more

Ryan