Of course, by no traumatic experience, one can assume no experience at all, or no traumatic, but neutral and/or good experience with water. No experience at all with water could lead a human to believe it is hate, when it may be mere aversion or severe disinterest. If there was force involved to get the dog to acknowledge the water or similar actions by the pet’s handler, could aggrivate this behavior.
You may have heard the adage about Portugese water-dogs and Labradors loving to swim, and this is true- they do have a natural affinity to water.
But within that lovely canine head lies a canine brain, and brains are known to have variation, because within any given population you will see variation in habits and mannerisms. A Portugese water-dog or a Terranova could be deathly afraid of water, where a golden retriver puppy (known for their aversion to water and swimming) might jump in before the Terranova even gets their nose to the shore’s edge.
And then comes the environment the dog was raised in – even being known to run and hide with the mere sound of the flea spray can or the tub being filled or what have you, can usually mean they may not like swimming. But then again, I have personally witnessed anachronims with dogs like this loving to do laps back and forth in small pools or massive lakes.
In the end, raising environment and breed are the most major factors in a dog’s affinity with water.