I’ve dreamed of doing stuff like this for years.
We built and sail 1/144 scale Radio-Controlled Model Warships from WWI and WWII which are armed with Co2 powered cannon and armoured in thin balsa. These vessels engage each other in combat on ponds across Australia, endeavoring to punch holes in each others hull with their cannon until one of the vessels sinks or flees. Yes, the cannon really do fire, the vessels really do take damage and sink, and yes, it is legal in all states and territories of Australia without a gun license.
Link courtesy of Make.