Chapter 5 · Try it yourself

Tide Clock

Monterey gets two high tides and two low tides a day, and they are never the same size. Pick a Moon phase, then slide through the day and watch the sea climb up and slide back down the rocks. Everything living there has to survive both.

Simplified model: a made-up but realistic day at Monterey built from one twice-a-day tide plus one once-a-day tide, measured from average lower low water (0 m, the zero on real tide tables). A typical day’s range is about 1.6 m. Real tides also shift with the Moon’s tilt, the season, wind and waves, and they arrive about 50 minutes later each day. Zone heights are approximate.