Ring of Bright Water (1969)

Whoever said dog is man's best friend never met Mij. Mij is a cute, cuddly pet-shop otter who captures the heart of Graham Merill (Bill Travers). It doesn't take Graham long to realize that London is no place to raise a slippery otter. So he takes Mij to live in a ramshackle cottage on the coast of Scotland. Together they explore the curious and magnificent natural wonders that surround their seaside home--from orphaned geese to toothless sharks. While Mij spends his days frolicking in the icy-cold sea, Graham falls in love with the beautiful town doctor, Mary (Virginia McKenna). Before long, the three become inseparable friends.