A Seal Called Andre:

This is the true story of the unique friendship between Harry Goodridge and Andre, the harbor seal who was as comfortable in Goodridges home as he was in Penobscot Bay. Andre became Rockport, Maines honorary harbormaster and was ranked "second only to Andrew Wyeth as the states most acclaimed summer resident." Year after year, Andre swam south in the winter, only to return again to Harry the next spring.