When I saw him do it was during the day and he seemed to be using the sun, but I didn't get any details.
The Capitol didn't want us going too far out on our fishing boats, because then we might run away. So it was illegal to have navigation tools. Everyone could tell general directions by the sun and stars and waves, but it was illegal to have a sextant or a map.
In other districts there was a fence to keep people in, but they had to let us go to sea to fish and there was no fence in the ocean. Our boats had trackers on them, but they still worried we'd get away if we knew how to find our way to somewhere outside Panem.
So yeah, I'd love to learn to navigate here.
How hard is it to make a sextant? I'm good at woodwork, if that helps, but the one I saw in Four was metal. I don't know how you'd make something like that here.