Rockland Harbor Breakwater Light, Rockland, Maine. Our tide clocks not only tell the time of high and low tide but the water moves up and down with the tide! It operates on a single AA battery. Set your clock to your local tide. (US Harbors' website posts tides throughout the United States). Tide Clock comes with instructions and is gift boxed. Measures 6.5" wide x 10.75" tall x 2" deep. Wood frame is navy blue. It can be hung on the wall or sit on a table top or shelf. Made in the USA.