Just in case no-one else has written an explanation: the phenomenon is called drawdown. As a vessel passes and blocks part of the waterway, because the cross-sectional area is reduced, the water speeds up to get past. From the conservation of energy principle, as the kinetic energy of the water has increased, the potential energy must decrease, so the water level drops, causing the drawdown. From the ship's point of view, this is called squat. Strangely, en.wikipedia.org/wiki/Squat_effect is quite misleadingly explained and the diagram is wrong.
This causes big problems with erosion in inlets that are used as passageways for large ships but are sheltered from ocean conditions and wouldn't naturally have large swells impacting the shore lines, it seems like a trivial thing but because the natural conditions inside an inlet are very calm and gentle the shorelines are made up of very fine sediments they are fragile it doesn't take long for ship displacement swells and waves to erode large amounts of shoreline sediments away.
Demonstrates... but not explains why it happens. Please explain why the water level goes down. Does it get sucked out by the propeller? Idk. Thanks. I cant find an explanation anywhere.
@@nix324 The link explains the "bank effect" which is a ship being attracted to the shore by a low pressure zone. I don't think it necessarily explains what happens in this video.
Even more fun to surf their wake. In New England only storms bring high surf so we have a buddy bring us out to the common gps path of Tankers leaving Jersey using an app. Once you basically can get on the wake riding it gets tiresome. 5 years ago we planned a day for it and got lucky. Sun was going down and I rode a 3ft wake for atleast 2NM
Crustaceans below the water mark suggest this to be a tidal region anyway. The video is a bit nauseating but brilliantly shows the erosion risk of commercial shipping lanes in narrow waterways.
This is cool. Crazy how the boat is big enough to displace the water even in a huge body of water like this. Also, who are the 393 people that disliked this video? Clearly you hate your lives.
It's really just the ship's movement through the water that creates a forward moving wave, the wave's energy corrals the water in front and sides of the ship. Once the ship passes the water on the sides of the ship collapse forward from gravity without the ship no longer occupying the space. You can easily reproduce this effect by filling your bathtub up with water and grabbing anything that floats and slowly push it from one side of the tub to the other. You will see the water in front of the object is higher than towards the rear until you stop moving it. The wave you created loses its energy when you stop moving the object, hence, the water quickly returns to its initial state.
I'm no hydrologist but I think you are right. It's not displacement per se. It's also friction in that it is wasted energy. The amount of energy to move that much water is huge and its happening throughout the ship's voyage. However, despite that, the amount of friction with a ship is exponentially less that any kind of land transportation.
@@Ryan-md1fc Half fill a bowl with water. Mark the level of the water on the side of the bowl with a permanent marker. Start placing stones in the bowl of water and see the water level rise. I wonder, if we removed all vessels (both floating and sunk) from all oceans and seas on Earth, by how much global sea levels would reduce.
Displace the water? Displacing the water would raise the level of the water. When a boat is put in a bathtub, the boat displaces water and the level in the tub rises. What causes the water to be sucked out. It’s not displacement.
This is between the Tx St. Aquarium and the USS Lexington on Corpus Christi. The ship channel is 60 feet deep and the area surrounding it is 8 feet deep. Lots of big waves.
AMAZING! Was like a planet passed only 150,000 miles! Thank you so much for posting this valuable and fascinating video! Such a contribution to society! Your IQ must be at least one standard deviation below the mean! Cheers!
What is happening is that the propellers on the ship are actually sucking water from around the hull and pushing it out behind the ship ... the surrounding water moves towards the low pressure area around the hull to replace what is being drawn away. As the ship passes, the high pressure area formed behind the ship, spreads out back to its normal neutral pressure state - thus the water coming back to shore.
bullllllshit... propellors have nothing to do with creation of the hp or lp zones...same thing would occur if the tugs brought in a 'dead ship'....it's the displacement the underwater body of the vessel creates that forms the different pressure zones. so what is actually happening is you are commenting on something you know very little about...
Jawadad - your theory would be correct if the water at the shoreline rose first, then receded, which is clearly not happening in this video. I used to work on such ships on the Great Lakes and have seen this phenomenon countless times. It is far more pronounced in narrow, shallow rivers, where water AHEAD of the vessel is drawn away from the shoreline, instead of being pushed up and over the banks.
Washington state. Lummi island has a low beach that they had to slow ships and super tankers down as the wakes would wash across the beach the road and into the first floors of homes there.
man the crabs and whatever stuffs be living inside the sand near the beach be like , " excuse me, where the fuck is water ? man, we can't have shit in Detroit "
I live along the port of houston ship channel amd they have probably 50 to a 100 big ships that come in and out of there everyday and everyone of em do that to the water level. But of course its probably 80 to a 100 feet deep too.
I wonder what makes draining near shore land, when billions of gallons of water on sea' ? Maybe the motor engines rotation so fast that siphoned water from distance. I wonder if a navy OSN siencetist could explain for this. I learned something new today about natural earth. Thanks for sharing this education video. Try ask the weather meteroligist about this and see what can he say.
I bet you this video was taken on the Side of the Corpus Christi bay Bridge on the side where the USS Lexington is permanently Moored alongside of the Texas State Aquarium. I have been in that building over the water MANY Times. As a matter of fact; I was Friends wuth the people who owned tgat building in 1971 through 1981. I fished from the inside of the boathouse they had underneath it. It was once called the Boathouse Restaurant, and The Boathouse Grill. It is directly across the street from an old motel which was once called The Lynn Motor Inn. You could read it from the tpp of the Corpus Christi Harbor Bridge. I have been there many times in my lifetime. It seems such a short time ago that I used to fish from the Jerry where the USS Lexungon is now moored.
Big John you would win that bet. I've been on C.C. North Beach for about 40yrs now. I bartend at pier 99 and remember the boathouse. Thanks for watching and always looking for new friends/subscribers
IDK what is up withe comments man, I was able to see quite easily that the water level was going down. Also, people can use the gear icon to speed the vid up if they want. Nice vid
Nøderak thanks for watching and your positive input. Lol. Negative comments don't get me down but positive ones sure make me happy. Always looking for new friend/subscribers
I just can't wrap my head around how something like this can make the water level drop. Is it not the same as putting ice cubes in a full glass of water?
When the ship moves forward it creates a vacuum behind it. Water rushes in to fill that vacuum which creates a current that pulls water from very long distances. This causes the water to get pulled away from the beach.
Thank you! I was sitting thinking displacement would make the water rise, then fall. I think that is from the ship's propeller pushing so much water out behind it, through the narrow passage (the venturi), that is sucks the water out - causing the water to fall then rise. Displacement videos are different.
A ship weighs as much as the amount of water that it displaces. Think about pushing a beach ball down into a tub of water. The harder you push down, the harder it will be to push down and the water level rises.
@@trentfletcher1942 To expound on your point... In order for a ship to float it needs to displace water with a weight greater or at least equal to than that of the ship. That's the idea behind density. A ten lb. solid iron ball will not float but if shaped properly a 10 lb. flat iron skillet could. So basically, the amount of water displaced UNDERNEATH the water line weighs as much as a the entire ship.
This is nothing more than water seeking it's own level. Big ships are pushing massive quantities of water. You can try this at home the next time it rains. Find a puddle and run a shovel thru the puddle. The shovel will push the water causing the water level to drop behind the shovel. As soon as the pressure caused by the shovel (think ship here) has passed the water returns to normal level. Basic physics on a large scale. Small boats do the same thing, but because they are small it's not noticed as much.
Random RU-vid video than bam right there in front of me the USS Lexington. Now I'm going to have to go down there and watch as the next big ship goes by.
USS Lexington, nicknamed "The Blue Ghost", is an Essex-class aircraft carrier built during World War II for the United States Navy. Originally intended to be named Cabot, word arrived during construction that USS Lexington had been lost in the Battle of the Coral Sea
Exactly 40,000 tons of water rushed back behind the vessel. It's called Archimedes principle. That's only 40,000 cubic meters of water. Not much really!
@@Scottish_sniper69 Where did the electricity come from? More than likely it came from a coal fired steam turbine or a gas fired furnace producing steam. Only 20% of electricity is not from coal fired turbines and gas fired funaces producing steam. Even the petrol in my tank was likely mined using some sort of electric power from these sources. I guess coal needs more credit than it is given. I apologise for not acknowledging it. Coal is saving lives as well. Probably more than petroleum.
This video gave me the best idea ever: We can stop the rising sea level caused by global warming just by having a few more of these ships sailing around. On local scale it’s most likely to prevent tsunami’s as well. Am I a genius or what!
Kayla Rigole thanks for watching and always looking for new friends/subscribers. Look up some videos explaining water displacement. Should explain better than I can. Water Displacement. Volume is a measure of the amount of space an object takes up. When a boats hull is submerged in the water it pushes water out of the way. If you measure the amount the water level increases, you can find the volume of the water pushed out of the way.
@@dazeschain2203 I have, multiple times. Plenty of vids showing the phenomenon.... but none really explain why, when a large ship goes by, the water recedes. One would think the displacement would INCREASE the water level locally. Not decrease it. I cannot find an explanation WHY this happens. Where does the water go? Why does it go there? Maybe one day ill find out.
Long Lasting the cargo ship displaces a very large amount of water, and you can observe that when the ship leaves the area the water level on the beach goes down
