A self-contained underwater time-lapse camera for in situ long-term observations

A self-contained underwater time-lapse camera system, based on a standard 16 mm movie camera, is introduced. The camera is capable of autonomous underwater operation up to 1 week — limited by the energy supply — and uses standard 30 m rolls of film with 4000 exposures. The system is equipped with two adjustable computer flashes, powered by a simple 12 V car battery. The camera is triggered electromagnetically, controlled by an electronic timer. The unit, with a total mass of about 25 kg, can be operated and positioned by a single diver even from very small boats. A maximum working depth of 50 m can be reached. First results and experiences with the time-lapse camera, based on almost 1000 h of operation in the North Adriatic Sea, are described and discussed.