Harbour Porpoise

Capturing the Harbour Porpoise requires a specialized approach since they inhabit the water's edge rather than the forest floor. If your 'backyard' includes a pier, dock, or a shoreline overlooking a bay, the best setup is a high-resolution trail camera or a weather-sealed AI camera mounted on a stable tripod or piling. Position the camera between 3 to 6 feet above the high-tide line, angled slightly downward to capture the surface of the water approximately 20 to 50 feet out. Because porpoises often 'roll' quickly, use a camera with a high trigger speed or set it to record short 10-20 second video clips triggered by movement.

Lighting is your biggest challenge. To minimize glare from the water surface, which can confuse AI detection and wash out the image, use a polarizing filter over the lens. The best time to capture footage is during 'slack water' or early morning when the sea is glassy and calm; whitecaps and heavy chop make it nearly impossible to distinguish a dorsal fin from a wave. If you are using a waterproof camera housing for an underwater perspective, mount it to a pier piling facing into the current. Porpoises often swim against the tide to catch disoriented fish, so a current-facing camera increases your chances of a head-on shot.

There is no traditional 'bait' for a porpoise, but you can leverage their natural rhythms. Research the local tide charts; these animals almost always follow the movement of their prey, which is dictated by the tide. Setting your camera to be active during the two hours surrounding high tide will yield the most sightings. In the winter months, look for areas where freshwater rivers meet the sea, as the warmer estuary water can attract both the fish and the porpoises that hunt them.

For those using AI-powered cameras, ensure the 'marine mammal' or 'large animal' detection setting is active. Because the Harbour Porpoise lacks a tall dorsal fin, the AI needs to be trained on the 'rolling' shape. Reviewing your footage regularly and tagging false positives (like floating logs or large waves) will help the system better identify these shy mammals over time. If your camera allows for time-lapse mode, consider setting a 1-frame-per-second interval during peak tidal windows to ensure you don't miss a fleeting surface break.