For some time I have been looking for a water based smoke unit for my Clyde Puffer, although it is possible to buy a commercial unit, I wanted something that would fit my boat exactly and after doing a bit of research, decided to build my own. The following list is the components that make up my current unit, some I bought and some I had lying around in the parts bin.
1 - 12v to 24v 3A 72W DC - DC Step up regulator - eBay 361245313528
2 - Ultrasonic mist maker - eBay 321548707355
3 - Micro 30x30mm fan - eBay 171440455054
4 - Speed controller - eBay (Maplin) 400807065840
After going through several configurations, trying to get the most out of the unit, whilst fitting within the constraints of the model, I found that the vapor units work best when they are under half an inch of water, with around two inches of clear space above the water, to allow the vapor to form.
With this in mind, I constructed the final unit from a standard electrical enclosure, with a custom clear acrylic lid, this worked well, but lake tests proved, that even with a modest breeze, the smoke effect is very quickly dissipated. To over come this, I installed another ultrasonic unit, which has dramatically increased the output, giving a pleasing effect, even on windy days.
To regulate the output, the fan on top of the unit is connected to speed controller, this allows the unit to be setup for differing conditions lake side.
To make the unit easier to use, I have recently installed a pump that fills the unit with water from the lake, which I can reverse to empty it again, in the future I plan to add a float switch to further automate this process.
Video of the first test of the unit in the model, this is with one ultrasonic unit:
https://youtu.be/G-hizJ8US14