Although Gyarados is the pokemon which sailors tell frightful legends about encountering, far more sailors have lost their lives in battle to Poliwrath. Poliwrath possess muscles nearly as powerful as Machamp and have enough strength to punch through all known types of sailing craft. They remain a danger to this day, as the advent of metal coating and thicker hulls has done little if anything to make this more difficult for their fists.
Wild Poliwrath are even rarer than wild Gyarados; it is the trained ones sailors must watch out for. Naval combat since the discovery of water stones has been fought below as well as above the surface of the water, as elite squadrons of Poliwrath battle platoons of other water pokemon, seeking to sink the ships which fire powerful cannons and carry soldiers to other battles. More ships are sunk by Poliwrath than by other ships, and because of the ever-present danger produced by this pokemon, navies in the pokemon world typically rely on small, fast boats which can transport soldiers and supplies as quickly as possible. A large cruiser is a sitting Psyduck.
In light of this, it is unsurprising that the submarine is also known as the mechanical Poliwrath. Militarily, real Poliwrath continue to be more valuable, and submarines have been slow to catch on.