The phrase "sail along" can be substituted with several synonyms depending on the context and tone of the sentence. For a more relaxed, carefree tone, one can use words such as cruise, glide, or drift. A more formal tone can make use of words like navigate, progress, or traverse. For a more adventurous tone, words like voyage, safari, or explore can be used. Similarly, words like float, bob, and coast can be used to denote a more leisurely activity. In summary, "sail along" can be effortlessly substituted with a plethora of synonyms depending on the desired mood and tone of the sentence.