foreshore

/ˈfɔrˌʃɔr/
noun
  1. The part of a shore between the high-water mark and the low-water mark, which is covered and uncovered by the tide.
    • The children collected shells along the foreshore as the waves gently lapped the sand.
    • At low tide, the foreshore is exposed, revealing tide pools and seaweed.
    • Environmentalists study the foreshore to monitor the health of coastal ecosystems.