This is the thing to get right, and it is specific to the bay side.
At low water the flats off Paines Creek, Breakwater, Saints Landing and Crosby Landing extend a very long way out, and the walking is easy: firm ribbed sand with warm channels between the bars. Children find hermit crabs, moon snails, slipper limpets and the occasional horseshoe crab. In the middle distance people look like figures on a beach in a painting, which is exactly what the appeal is.
The tide comes back in across a surface that is nearly flat, which means it arrives as a widening sheet rather than as an advancing edge. Channels between the bars fill first and they fill behind you. People who walked out on a falling tide and did not watch the clock find themselves wading a chest-deep channel between them and the beach.
The rule is simple. Go out on a falling tide, turn round at low water, and be back before it has risen far. Use a tide table, not a guess, and note that low water is roughly fifty minutes later each day.
Wear something on your feet. Broken shell and the occasional crab make bare feet a poor decision out there, and the sand heats enough on a hot day to matter on the way back.
Finally: the flats are not a beach you can swim from at low tide. If swimming is the plan, come on a rising or high tide, when the same shoreline is a warm, calm, shallow bay.