Signal for hove to?

[Dr. D]

I plan on sailing out the Chesapeake Bay onto the Atlantic this year. Before then I plan to develop a sleep pattern to permit me to sail at night. However, if I become too exhausted I may have to heave to. If so, what signal should I show? Remain with under sail lights, or anchor light?

Yes, I know I still sails up, but the boat is barely moving. Almost like anchored.