Newfoundlands were bred to be work dogs, hauling sled and cart goods that needed to be transported in a time before mass transport over extreme distances. They soon became staples on ships because of their hereditary physical and personality traits.

The Newfoundland dog's extremely fit legs and webbed toes make swimming a cinch for them. They also possess lungs that allow them long periods under water. And the Newfoundland's water resistant double coat keeps him dry and warm near his skin. It was not long before captains of ships saw a potential asset in the heavy-set breed.
Captains began using the Newfoundland to haul fishing nets and to carry tow lines. The Newfoundland was also useful for when objects or people were thrown or fell off of boats. And although he is not the snow dog like the Saint Bernard, the Newfoundland has been known to use his girth to break ice to get to drowning victims. His strong legs and lung capacity give him stamina to go long distances and fight unrelenting waves.
The usefulness of the Newfoundland at sea was known internationally during the time when sailing ships were the one main means of transport over long distances. His powerful lungs, his dedication, and his instincts were great benefits to a ship. The specific duty of a Newfoundland then was to swim ashore with a line, thus communicating to those on land that help was needed. The Newfoundland was able to traverse sea rocks that even the most surefooted seaman could not master.

What makes Newfoundlands remarkable is that they are so calm in a drowning victim situation. They are not fearful of the water, and they do not need to be taught how to swim. They quicken a rescue mission and they save rescue authorities time, money, and resources in training them since they already know what to do. And the intelligence of this breed just furthers the argument that they are as essential to a ship as a crew.

The Newfoundland will, without being instructed to do so, place a drowning unconscious person on their back with their head above the water. If two Newfoundlands are near to a drowning person, they will tag team. One will automatically take one arm and the other Newfoundland will take the other arm and drag a person to safety back on land. A Newfoundland will first circle a person who looks like she/he might be in danger, then he will nudge them, trying to get them to take a hold of him, encouragingly. If the person does not take the offered help, the dog will physically carry with his mouth a person he suspected was at risk of drowning. Newfoundlands are undoubtedly one of the best gifts nature has to offer.