Why did Brian chose to locate his shelter close to the lake?

Brian chose to build his shelter near the lake in case the plane could be seen by a plane flying overhead. If the plane was seen submerged in the lake, he might be rescued, thus, he wanted to stay nearby.

He wanted to stay near the lake because he thought the plane, even deep in the water, might show up to somebody flying over and he didn't want to diminish any chance he might have of being found.

BOIIIIII FINE I WILL ANNSWER BISH IT CUZ HE COULD GET WATER FASTER