Dead water

Dead water  is the nautical term for a phenomenon which can occur when a layer of fresh or brackish water rest on top of denser salt water, without the two layers mixing. A ship powered by direct thrust under the waterline, traveling in such conditions may be hard to maneuver or can even slow down almost to a standstill. Much of the energy from the ship's propeller only results in waves and turbulence between the two layers of water, leaving a ship capable of traveling at perhaps as little as 20% of its normal speed.


Dead water is the nautical term for a phenomenon which can occur when a layer of fresh or brackish water rest on top of denser salt water, without the two layers mixing. A ship powered by direct thrust under the waterline, traveling in such conditions may be hard to maneuver or can even slow down almost to a standstill. Much of the energy from the ship's propeller only results in waves and turbulence between the two layers of water, leaving a ship capable of traveling at perhaps as little as 20% of its normal speed.
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