I'm not an expert on this propulsion style by any means, I've only built 7 or 8 jet boats in my entire life without really knowing the science of it all, but every one has worked out great.
Real time on this video took about an hour, 45 minutes being marking out the holes before the first cut!

I intended on posting another video for the rest of the build that simply involves mounting the servos, running water lines and connecting the electonics etc but its so basic and boring I didn't bother

Please subscribe to my channel and ill continue posting rc boat how to's.