Navigating underwater is crucial for scuba divers. To use a compass effectively, first set your heading by aligning the lubber line with the compass needle. Choose a visual reference to swim towards, rather than constantly staring at the compass. While swimming, maintain a steady kick and check your compass occasionally. To find your way back, rotate the bezel 180° and repeat the navigation process. Familiarize yourself with distance measurement techniques and practice in calm waters before tackling challenging conditions.