550engine in riverboat.. What impeller should i use?

[ISeeWetPeople]

hi

i have this crasy project done and i need some help..
i just put 550 engine to wooden river boat.. and it runs good and fast 37km/h but it does gavitate a lot.. what impeller should i use ? i need low end most to dodge rocks and climbing rivers buty speed is good to have too

 

[Nottjbarlow]

13* is stock on a 440 pump i believe, the cavitation is probably due to the pump having a hard time getting water without air.....

Just my .02

There's some footage of my old jonski in this video....

 

[ISeeWetPeople]

funny video=)

here´some action of that boat