Levels with an ocean theme

From Sonic Retro

Sonic Retro emblem.svg Level themes
Ocean theme
Metal Harbor from Sonic Adventure 2 is an example of the ocean theme.

The ocean theme represents levels that are set by or on the surface of an ocean. This theme first appeared in Oil Ocean Zone in Sonic the Hedgehog 2.

These levels are often set at the coastline of an island or other landmass and thus can have overlap with the tropical island theme, such as Seaside Hill. Some ocean-themed levels may also be set on man-made structures atop an ocean's surface, such as Metal Harbor. The ocean itself may either feature underwater areas, function as a bottomless pit, or is simply a background piece.

Levels with an ocean theme