The Squat is used in extremely shallow situations where, due to the bottom, the Belly Bottom is not possible. This technique does tend to be tiring and uncomfortable. However, it is very useful for evaluating small sites before deciding to explore using another technique, you simply walk from one potential site to another, then squat and stick your face in the water.
Safety Tip: Move slowly and stay in control. If you lose balance while entering The Squat, you may end up doing a facer into the water.