The phrase "of sea" can be expressed in a variety of ways depending on the context and message that is being conveyed. Here are some synonyms that can be used in place of "of sea": oceanic, maritime, aquatic, sea-bound, coastal, marine, saltwater, pelagic, seafaring, nautical, ocean-bound, briny, watery, littoral, seagoing, blue-water, reef-filled, tidal, surf-filled, submerged. These synonyms can be used interchangeably to add depth and variety to your writing when describing the sea or anything related to it. Whether you are writing a story, poem, or essay, using synonyms can help elevate your language and engage your readers.