There are a few paddle maker sponsors, but also more than a few makers of solo-rec size canoes. The northernforestcanoe.org now operates the annual 41 year old Adirondack 90 mile classic canoe race, but has been in charge only since past 3-4 years, and also a few other races in NY and New England. You can see their sponsor list online. But once again, class designations are set by the ACA.
However, I see nothing on the ACA national website that would require a DB paddle for solo-rec racing. The individual local race officials set those rules. AFAIK, since its inception, the 90 miler has had a solo-rec class which demands DB paddle use (I have been in that race in various canoe classes continuously for 30 years).
