Oystercatcher 18cm Tide ClockVery useful for knowing when the tide is out or in for beaching, boating or fishing. All you do is set the clock on a high or low tide when you know this time and it adjusts every day automatically from then. All you then have to do is every six months or so is check accuracy against accordingly. Made from toughened glass, these stylish clocks are heat and seam proof. Perfect for hot steamy kitchens or bathrooms. 18cm in diameter. .