The phrase "most boating" can be substituted with several different synonyms, depending on the context in which it is used. Some potential options include "largely nautical," "predominantly sailing," "primarily maritime," or "essentially aquatic." Other possibilities might include "mostly seafaring," "mostly voyaging," "mostly cruising," or "mostly navigating." The choice of synonym may depend on the specific topic being discussed, as well as the tone and style of the writing or conversation. Ultimately, the goal is to find a phrase that accurately reflects the idea of "most boating" while conveying the intended meaning and tone.