The owner of coastal property ordinarily has riparian rights or littoral rights that go with the ownership of the waterfront property. These rights may include the right to install a dock, to control fishing, to use the beach or tidal zone, to moor boats and to store property on the shoreline. Where neighbors along the coasts are increasingly close together and actively using the property year-round, conflicts can develop.
My regular practice is based in states that border all of the Great Lakes and the Atlantic Ocean. Along with the Gulf of Mexico and the Pacific Ocean, these coastline areas offer thousands of miles of shoreline property where businesses operate, municipalities draw water, marinas operate and individuals have homes for vacation and year-round residences.
These individuals and corporations have an interest in balancing their rights and uses of their waterfront property not only with government regulation but also of public interests held in trust by the government at the water's edge in some jurisdictions and competing interests of neighbors on each side to have access to the water in all conditions and coastal configurations.
Example: the Massachusetts rule
One issue common to most coastal jurisdictions - both the ocean coasts and the Great Lakes coasts - is how to determine where the side boundaries are between neighbors for purpose of defining the limits of each owner's rights to use and control the beach, the tidal zone and into the water, whether to install a dock or to exclude a neighbor's activities from one's view or competing use.
There is a national body of common law on this issue, with decisions separately decided in each jurisdiction at the state level but sharing a common history going back to English common law. More to follow on this shared concern.