hi Tom, thats an interesting detail, the link at http://www.boatdesign.net/forums/showthread.php?t=1887&highlight=jump shows (when looking good) the same nozzle on another jumpcat. is it to create more steering force, improve thust or for beaching protection? maybe all reasons? i'm sure its not for show!
Safety for people.protection for prop.=drag. price you pay for a little more saftey for drivers and public.still good performance though.Can be made much more eloborate.increase the cage struts.still good performance. tom kane