Squares and Rectangles
Squares and rectangles cover more area, and suit both natural and compass navigation. Three legs of a square/rectangle are usually the easiest way to navigate around an obstacle. You may or may not have to measure distance to get a useable pattern.
An example of a natural navigation rectangle pattern would be to swim out from shore, turn 90 degrees and swim parallel to shore, then turn 90 degrees toward shore. In shallow water, you turn 90 degrees to swim parallel to shor