Hi Peter, had one of those Eureka! moments, and it was so simple I hadn't thought of it!
JB

Re Get the Patent first JB,👍
But how will I stop certain 'reverse engineering experts' 😉 copying it Doug. Perhaps call it a vape machine to put them off the scent😀? 'Thinks' blast! I've already told them how I did it. Never mind, now we'll soon be able to buy one off Ali Express. Once had an idea for a pen with a triangular letter opener on the top end. Years later I went to a pop-up Chinese nic nac sale in a rented warehouse, and guess what was there??!!!☹️ They are obviously employing psychics to walk around jotting down peoples' ideas😮
I also still have 5th form (1968) sketches I did for a hybrid go-kart using a Briggs and Stratton motor driving 2 alternators charging twin 12v batteries driving electric motors on the back wheels with chain reduction drives, WHO KNEW???
JB (the too late inventor)

More smoke and less water and you've cracked it!
How you will manage to get the water to just spit out in bits/pulses will be the biggest challenge I think.
As you said you can blow more smoke in.

Martin555.

"Koi carp (Chinese sub)"
Er ... that's the JDF, Japanese Defence Force sub JB.
Didn't get seasick, but it did 'make me eyes go funny' 🤓
This can never work for more than a minute or two cos you'd need to have absolutely identical performance of ESCs, motors and rudders (perhaps also hull forms) in both boats.
I tried it once with my destroyer and Sea Scout - no chance!
Had more luck 'escorting' a same scale (1/72) Flower Class corvette around the lake in the Olympia Park, Munich ca 3 decades ago 😉
😎

This vid is cut down from around 20 mins Doug. Each boat is totally independent of the other as one is on the left stick using one RX (elevator and rudder channels) and the other on the right stick using a second RX (throttle and aileron channels)
I think everyone has the idea that they are on the same stick? The eyes do go a bit wonky as the camera is only a small keychain camera (pre Go Pro days) which we used to mount on planes etc, and the boat movements are quick.
You can always change the playback speed (on the left of the You Tube logo)
JB PS I'm sure I saw a red star on that carp!

Re - Small table to rest the trannies on
What Doug said Ken,😀 Was easier before I changed to twin throttles as I had each boat on a separate stick.
JB

Re - Well what do you expect livin' on yer 'eads
Probably something to do with the space time continuum Doug, did you know the water runs the other way down the plughole down South (or up South if you want to be contrary) Mind you, the blood running to the top of the head makes us think differently (same with the Aussies, although they think slightly more left than us😊
JB

Re - It was just a loose idea, maybe a bit of copper tube
I think I am just going to run out of room after checking dimensions Martin. It would have to go under the rear cockpit floor and I just have too much in there already, (2 battery packs and all the tubing)so I might flag it for now, and if I get a brainwave later I might re visit the idea.
I agree with what Doug said about trying to get things working in such a small scale. There will be a way, just haven't found it yet. Custom made may be the only answer. If the boat had a full cabin it would not be an issue, but the low cockpit floor layout limits you a bit.
JB

As you say Jb,
Something for a future project.

Martin555.

JB we have an odd shop here - called the "Crazy" store - you must have similar ones there - full of Chinese stuff and gadgets etc. One of the pool/beach type things they sell are kiddies paddling pools - usually inflatable - which are not much use as a test tank - however better half found one with a semi solid wall - that does the job admirably . Have a good look - sure you could find one too. Save you the hassle - easy to erect and useful when you need it.......... Packs away into a small box.

Actually thought about that Red, not a bad idea but I'd have to buy a pump as these days I'd probably black out trying to blow one up manually. Nice and soft round the edges as well, won't damage the boats. Main problem for me is my entire section is sloping and the only flat area available is a strip of concrete on the drive, or else the deck. I made this one narrow as it doesn't take too much water to float the boat.
JB

Now all you need is the FPV system! Nice fix.
JB

That's very nice!
You should make a video of it.
under sail that is!

Love to see one built and working. Design very similar to an ice yacht which I imagine would be incredibly fast on a good flat piece of ice. First time I saw an ice yacht was on a frozen lake near Les Rousses in the French Jura. Pull the sheet in and they'd be down the other end of the lake is seconds. Always fancied trying a real one, land or ice or both. Think it would be a great experience.
We watched the ice yachts for a while, then drove on down, about an hour, to Geneva, beautiful warm sunny day with real yachts sailing on the lake.

Hi Bryan,

Jaws looks very good.
I can't wait to see it in action!
An under water video would be good!

I hope for not to much underwater footage as jaws is a surface runner with a lot of the shark above the waves.

And the prize goes to..., perhaps if I (thr) hum along Doug?😊 (see reply to Martin for answer) It's real hard to get just the right sound to match a model (the sound units I have are not too bad) but there must be ways of doing it without having to spend lots of money on complicated sound units with set programmed sounds. In the case of my sound units, they are real engine sounds, programmed to be proportional on internal SD card but they don't quite match the model). A lot depends on the internal volume of the model (resonator), sound unit and speaker/placement.
The search will continue for a cheap alternative.
JB

She's not a turbo!