Zeus & Roxanne (1997) on Netflix

Plot summary

Mary Beth Dunhill, a marine biologist, lives beside Terry Barnett, an aspiring musician raising his son, Jordan. Their dog, Zeus, wrecks her garden and then follows her to work, stowing away on the boat she takes out with her research partner, Becky, to follow a dolphin they name Roxanne. Zeus slips overboard, and Roxanne saves him from a shark and carries him back to the boat, astonishing the two researchers with what looks like communication between species. Mary Beth asks Jordan to lend her Zeus for her study. Terry and Jordan come along on the research trips, and her own daughters, Judith and Nora, are part of the household. Claude Carver, a rival researcher, wants the same grant.