Re: AIPs,WaterJets and Propulsion

["Sean Walinga" <swalinga@telusplanet.net>]

>I must be missing something here, because I don't understand this discussion.
>This seems to imply that air pressure is driving water jets, and a trolling
>motor is used to 'start' the flow.  This is not at all what I understand
>'waterjet' propulsion to be.  Can someone help clear up my misunderstanding?
>
>Stan

Hi Stan,
Mike's idea is to create a jetski waterjet while submerged. These waterjets require the air supply to create a vacuum on the intake side of the impellor. Other waterjets that you may be thinking of use an impellor with a thrust tube but don't create the same sort of jetski waterjet. The trolling motor is not needed to start(prime) either waterjet. Next time you ride a jetski, take notice of the propulsion. The jetski power will increase dramatically when it gets a bit of air in there. The vanes at the waterjet intake are designed to increase the amount of air as the machine moves faster. When starting from standing, it uses mostly water with little air. There is quite abit of info on the web due to each manufacturer being soooo proud of the way they do things...  :)   This pride is partly based on their specific ratio of air to water and the power that results. This is the reason that I question the subsurface jetski waterjet.

Hope this helped.
Sean