The phrase "across sea" commonly refers to traveling or communicating from one shore to another, usually across a body of water. There are several alternative terms that can be used as synonyms for this phrase, including "overseas," "transoceanic," "crossing the pond," "crossing the channel," or simply "across the water." Each of these terms emphasizes the idea of spanning a significant distance and crossing a barrier to reach a new destination. Depending on the context, one of these phrases may be more appropriate than "across sea" for describing a voyage or communication that takes place across an ocean or other large body of water.