Last time I checked, running lights were required for all vessels, powered, sail or rowed. You may want to take a look at
If you want specifics for each state, especially Florida, try rowing through Boot Key Harbor in January at night with no lights at all. Someone in a uniform will politely explain the law to you, chapter and verse, while he or she writes you a citation that will really piss you off. Same holds true with anchor lights. There were a lot of unhappy campers that thought because they were on a mooring ball they didn't need anchor lights - WRONG! Yep, they were cited as well.
Good luck on staying alive very long while running that dink at night with no lights.