It's not idiomatic to say the "bank of an ocean", only of a river or stream, but the word is used to describe one aspect of the ocean: "a broad elevation of the sea floor around which the water is relatively shallow but not a hazard to surface navigation." http://dictionary.reference.com/browse/bank
Thesaurus.com says, for example:
"Definition: sandy area by body of water
"Synonyms: bank, coast, lakeshore, lakeside, littoral, margin, oceanfront, seaboard, seafront, seashore, seaside, shingle, shore, strand , waterfront"