I think that an under .21 Race would be a good promotional idea...
The Bad News:
One of the things that keeps the under .21 crowd from growing like many others have said. There are very few "racing" quality kits or RTR being built right now. Most of what's available is plastic hulls that are not designed to last a season of hard running. Also, small light-weight boats like the under .21 are traditionally not very well suited to windy or choppy water which makes them hard to race in areas where water is not flat.
I think that there is a missconception that an under .21 boat is a beginner boat? They are not -Especially the under .21 riggers -Which currently are the only good wood kits available at a reasonable price.
Also, the current nitro course is just too big to run a .12 boat. It can and is done everyday by experienced boaters -but put a green thumb behind the wheel and you better warm up the motor on the retrieve boat... I wish that the electric course be the one that is used for the under .21 class. It wqould be more appropiate for the size of the boat and easier to see the boat in the back straight-a-way.
The Good News:
We already have a few racing kits specifically designed for small-block engines. Like the Fire Fighter, and some Monos. Some of the 24" electric fiberglass Hydros can be modified to run a small-block engine with good results. Ron -Better get the HH12 out before you miss the boat.
So basically we have a small group of nitro boaters who also tinker with custom-built .12 boats and run them mainly for fun.
The trick is to lure them into racing with other miss-matched boats and eventually grow the classes so you don't have a rigger racing against a cat. I think that as an exhibition class the under .21 are probably going to do okay. When you open the door to organized racing -many racers will miggrate over to more convetional classes where better hulls/engine/equipement and regulations (Classes) exist.