Over a century ago, a fishing vessel encountered a mysterious "sticky" seawater in the northwest Atlantic. The crew suspected a sea monster was at play, but it wasn't until the captain discovered the stratification of the seawater that they realized it was the phenomenon known as "density stratification." A similar occurrence was documented by Norwegian explorer Fridtjof Nansen on his ship, the Fram. After more than three years of research, Nansen unveiled the scientific principles behind this phenomenon. Modern deep-sea submersibles, such as Jacques Piccard's Trieste, have also faced similar situations but ultimately managed to overcome them. While "density stratification" no longer poses a threat to contemporary vessels, its military applications remain extremely significant.