The sea is always coming and going. Twice a day the tide goes in and out. Every few million years, the coastlines are shifted miles in and out. If you've ever seen a monthly tide chart, or a line graph of transgressions and regressions through geologic time, the images are strikingly similar. One of the great convergences of these two periodic ocean pulses are Georgia Barrier Islands. Long-term sea-level changes make barrier islands possible while Oceans get bigger. The moon-coupled short-term tide ebb and flow make the salt marsh possible. The salt marsh makes Captain D's possible.
The picture here shows the result of tide pulses acting on sediments every day between the islands and the land, away from waves. This is what it looks like at low altitude from a small plane full of friends. A whole load of marine organisms uses this cushy zone for raising tender young that grow up to be your tender fish sticks and popcorn shrimp. Sam eats shrimp and blue crab. He also thinks barrier islands and marsh are good offspring-raising grounds for humans.
That's why we know about things like tide and have the sense to ask about historic sea level at the largest scales. Because there are some people who are willing to be in, and become part of, a place. To watch its rhythms, to appreciate its beauty and its part of the story. By lightly populating the right spots on Earth with watchful people, and connecting them to a network of askers and listeners, we can almost hear the planet breathe. Tide charts begin to look like EKGs, seasons wiggle the toes, sunrises and sunsets blink and see.
It's a big rock. Somebody's gotta watch it.