It is a sort of lonesome feeling to fly out over the ocean in a land plane. The pilot always realizes that if his engine quits, he must land on the water, and that his plane will float for not more than four hours after hitting the water. Accordingly, Bill wanted to get as much altitude as he could and at the same time accurately observe the falling shots. If his engine quit, he would then be able to glide at least part way back to shore. There is always the possibility of having to swim after a forced landing in the water, as boats are not always conveniently available for rescue work.