Do we know anyone custom printing props that could give me a prop with bit more speed?
For a small, easily driven boat, look at APC props. They produce mostly for the R/C airplane market, but have also started producing marine props for human-propelled boats (used by some R2AK entrants).
I've been using an APC 11x6 sport prop with a 480W motor to move my Windrider 16 trimaran. Top speed above 8km/h. Not bad for a $5 plastic prop - although I also added a spinner to reduce drag under water.
cpcanoesailor