Let's start from the legend about Newfoundlands.
It is the story how this breed helped people long time ago and maybe it still does in such a way.

It is considered that Newfoundland dog breed comes from Newfoundland Island. There during fishing, which may last for 120-160 days, dogs have to work hard and do a lot job. For example: fishermen sent the dog into the water to catch the floats of a fishing net and then to drag it on the shore. If some fish released from the net the Newfs would dive after it. Also in case the oar or any other instrument falls into the water the dog immediately and without even any order would jump into the water to catch the fallen object. Newfoundlands would go into the water by themselves and dive nearly vertically at the depth from 3 to 4 meters picking up from the bottom different things. They were and still are able to swim long distances under the water, just like otter. From time to time leaning out there heads to grasp a portion of oxygen.
On the Newfoundland Island dogs lived exceptionally on the seashore and sometimes on the ships. Very often one could meet them swimming in the open sea. Being on the ship they felt the smell of the land which wasn't even visible and informed the crew with load barking (the distance between the ship and land could achieve 10 miles (16 kilometers). In the same manner they informed when on the land about approaching ships.

Now several true life stories from Newfy owners

One Newfoundland owner told a story that one frosty winter his house was attacked by mice. The mousetraps which he was offered by one of his friends were not like steel traps but were organizes in a form of net house with slamming door. One morning he woke up and found in one trap one big live mouse and he had something to do with it. He couldn't bring himself to kill it and he invented nothing but to release it out of doors. So, with all his humanity he took the trap with the mouse. It was midnight (he didn't want his neighbors to think he is feeble) and together with his dog-friend Newfy whose name was Kid went to the garden and let the mouse to escape onto the snow. The mouse has disappeared instantly. After 40 minutes of walk on the fresh air they directed themselves back into the house. Suddenly the men saw that from the Kid’s mouth was hanging some kind of thin grey string. He was surprised (cause his Newfie wasn't a kind of vacuum cleaner-dog who picked up everything from the ground). He said to give it to him. And the Kid put into the hands of his master a caught mouth. The mouse was lying on his palm with its paunch upwards, folding its legs on the paunch, moving its nose and screw up eyes, all in Kid’s slobber but fully safe and sound. The Kid was absolute Newfoundland. He didn't let to escape and get lost to a very valuable pet.

One more story happened somewhere in Russia. A guy was walking along the street with his Newfoundland one cold winter day. Suddenly his dog called Flint began to dig in the snowdrift and dragged out a little (maybe 2 days old) frozen kitten. The guy 3 times throw away seemed dead kitten but when he finally came home Flint again spit out of his mouth nearly lifeless body of a little creature. And the dog was right in his deeds, because the kitten was still alive. They managed to warm the kitten and then feed it with a help of medicine dropper. This kitten became integral part for the rest of his life for these two rescuers.