A while ago, Mountfleet Models brought out a kit of a WW2 chariot, a most unusual subject. It's proved to be quite popular, so R&R have designed and built a module especially for the boat, based upon a water pump system.
The battery can be accessed from the front with a tray for a 7.2v pack built in, and also incorporated is a 1.5:1 reduction gearbox as the model uses a large ish prop.
There is a built in ballast tank that holds around 1/3 litre and its all piped up for a simple vented system. We don't supply a pump as many have one kicking around in a junk box.
The water baffle is run horizontal, as it seems to reduce water surge better than the usual vertical layout.
We have tried to keep prices within the realms of reality, this one is just £175 complete as you see it here.