The tide is the most reliable system on Earth. Twice a day, every day, the ocean rises and falls in response to the gravitational pull of a rock a quarter of a million miles away. This has been happening for four billion years and will continue long after we are gone. There is comfort in that.
Tidal zones are among the harshest habitats on the planet. Twice daily, every organism in the intertidal must survive being submerged and then exposed, drowned and then desiccated. The creatures that thrive there — limpets, barnacles, anemones — are not glamorous, but they are extraordinarily tough. They have solved a problem most of us would consider impossible.
I try to visit the same stretch of coast at low tide each month. The rockpools are never quite the same twice, which is the whole point of going back.