Which navigation pattern is characterized by moving in a straight line out and returning on the same line?

The navigation pattern defined as moving in a straight line out and returning on the same line is known as "out and back lines." This method allows divers to efficiently navigate to a specific point underwater before reversing course to return to their starting position. This technique is particularly advantageous for monitoring specific areas or when visibility is limited, as it provides a clear and direct path both in and out, minimizing the chance of becoming disoriented or lost.

In contrast, the other patterns serve different purposes. For example, squares or rectangles involve moving in a series of straight lines at right angles, allowing for broader area coverage but lacking the simplicity of a direct return path. Triangle patterns involve navigating in a triangular shape, which can be more complex and is often used for searching or exploring an area rather than simply returning to the start point. Circle patterns, as the name suggests, involve navigating in a circular route, which is useful for maintaining position in a spot but does not facilitate the straightforward return that the out and back method provides.

Thus, the out and back lines offer clarity and simplicity, making it the most effective choice for the situation described.