In the Inside Passage, the strait separating Vancouver Island from the mainland of Canada and Alaska, there is an intersection, where the protected waters of the Passage are met by the rougher waters of the North Pacific Ocean, between islands.  You can actually see where the waters meet, because they form a whirlpool with rushing and clashing of calm and excited.  The sound you hear is weird, because you almost can’t place it, or tell where or why it is happening.  Here, the invading Ocean waters meet the calm Passage waters.

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