Decided to keep moving east slowly to avoid further problems. We went through locks 15 & 14 and then we started hearing a rattling noise from the prop area. We turned around and docked at Canajoharie Free Docks with power. Greg went diving to check prop in 58 degree water! Greg indicated the prop seems ok but, the zinc and cone coming off drive shaft is spinning and he could only tighten the zinc the cone wouldn't budge. We consulted Dave at 4C's he said it shouldn't hurt anything, just take it slow. We were told the closest place that could handle hauling us out would be in Schenectady.