The boat that went with us this past spring was single-handing. He had a couple of challenging times, with the currents wanting to spin the boat, but he made it OK. One of the lock keepers didn't seem happy about it, but they did help as needed, and the rest didn't seem to mind. Letting them know ahead of time will help, there may be a more settled spot in the lock that they'll direct you to. Or at least be prepared to help.