(1)Any part of the sea-shore to the low water-mark forms part of the community or communities which it adjoins in proportion to the extent of the common boundary.
(2)Every accretion from the sea (whether natural or artificial) forms part of the community or communities which it adjoins in proportion to the extent of the common boundary.
(3)Every accretion or part of the sea-shore forming a part of a community under this section also forms part of the principal area and preserved county in which the community is situated.