Wind-driven waves and rising tidal water push seawater through a home's ground floor. A standard homeowners form treats this as:

Explanation

Surface water, waves, tidal water and overflow of a body of water fall inside the water damage exclusion whatever pushed them ashore, so the flooding is not a homeowners loss; cover comes from a separate flood policy, such as one written through the federal program. Calling it windstorm because wind drove the waves is the error the exclusion is worded to defeat. The accidental discharge peril reaches plumbing inside the home, not the sea.