Re: Screw size and speed

[SFreihof@aol.com]

In a message dated 7/21/99 6:58:50 AM Eastern Daylight Time, 
wolfe19@megsinet.net writes:

<< For ducted fans, both undrewater and above water, if the cowling is 
relitivley close fitting, efficancy can be markedly improved.  the propeller 
don't have the spill off at the tips creating those wingtip vortecies.  >>

The propeller shroud is called a "Kort Nozzle."  I haven't been able to find 
much information on design or sources for supply.  Anybody else?

Stan