The most obvious change is due to tides - where the coastal land is exposed at low tide and submerged at high tide.
(The most obvious change; is; due to tides) (the coastal land; is exposed; at low tide; L:tides) (the coastal land; submerged; at high tide)
The most obvious change the coastal land the coastal land
is is exposed submerged
due to tides
at low tide L:tides
at high tide