A functional lock for your rc tug, the 1st I've ever seen.
How much weight can you float? A functional hopper barge would be a nifty build.
I've been thinking hard about tugs & barges, be a good dirt work project for the fleet in the backyard to work at.. some of the equipment I've aquired lately, the basement is much too small for them; a river system would be a good long term (seasonal

) project.
Links to other clubs is perfectly acceptable.