It's probably better to just stick with people who are used to this sort of thing, if possible. Four or five of us could take 2 hour shifts.

...I usually don't sleep very much, I could probably take 3 hours, if need be. [Not knowing several of the newer Travelers, he's not sure which, if any, of them have experience keeping watch. He figures Riddick, Malik, and Mikasa are safe bets as far as that goes, though, so even with just them, they probably have enough.]