In Portugal, they’re called cau de agua or “dog of water,” and not surprisingly, Portuguese Water Dogs trained to help fishermen while they were out at sea are excellent swimmers. Porties (as some folks call them) pulled in nets, fetched items that fell into the water, and even “herded” fish into the nets. These superbly athletic dogs can dive as deep as 12 feet to herd the fish in the right direction. Some accounts even suggest that the dogs carried messages between ships of the Spanish armada.
We came across this short video you might find interesting: