4 hours on and off suggests two people. That schedule is tough especially if you add cooking and eating, and getting your gear on and off. Especially if you add in the possibility of sea sickness or disability. Your ability to sleep may be less too because of the conditions. Three people make it much easier. As it is a delivery voyage in effect he pays for the food. I also suggest meeting him beforehand. A tired martinet makes a very unpleasant environment with little opportunity to deal to him or get off.