"Chopping sea" is a phrase that describes the rough and turbulent waters that are often encountered during boating and sailing trips. Other synonyms for this phrase include "choppy sea," "rough sea," and "stormy sea." These terms all convey the same idea of waters that are tumultuous, with tall waves, strong winds, and unpredictable currents. Other related terms might include "swells," "whitecaps," and "breakers," which denote specific characteristics of waves in the sea. Whatever term you use, the key takeaway is that the sea can be a volatile and dangerous place, requiring skill and experience to navigate safely.