Why are ships so slow?
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Why are ships so slow?

November 19, 2019


  • Reply Casual Navigation May 11, 2019 at 8:09 pm

    Thanks for the amazing response everyone. I just wanted to address a few points raised in the comments. I like to keep things as accurate as I can so do continue call me out when I get things wrong and I'll correct anything needed.

    Hull Speed – is not actually a speed limit. As many have pointed out, it is just when the vessel's length equals the bow wave length. It doesn't actually restrict a vessel's speed.

    HP – is used purely for ease of comprehension as it is easier to visualise than kW.

    Drag – it does depend on numerous factors, but I kept it as a cross section alone as the main point was to illustrate the way it increases with speed.

    Obvious Answer – maybe, but the purpose of the video is entertainment. I have plenty of tutorials on the channel so am making videos like this for fun.

    Again, thanks for watching!

  • Reply jakezarkowski August 13, 2019 at 2:10 pm

    i clicked on this video for that little snail on the island

  • Reply Matt August 13, 2019 at 3:37 pm

    Sad that people don't already know this.. Have you never tried to walk in a pool?

  • Reply Incognito FLA August 13, 2019 at 11:01 pm

    100 HP cars? You are either misinformed or I feel sorry for whoever is driving 100 HP tin can cars. 6 Cyl Lexus – I get 300+ … my son's 4 Cyl Camry gets 200+. I guess in England restrictions are so tight everyone drives a sputtering cannot get out of the way tin can. Liberalism & lefties smacking down the populous with fuel+++ taxes.

  • Reply Slappy August 13, 2019 at 11:48 pm

    Why are ships slow?


    Everything is racism.

  • Reply A Rock. August 14, 2019 at 12:54 am

    Because of Earth patch 1.1.89, the boat speed limit was limited.

  • Reply Shane Riley August 14, 2019 at 11:42 am

    Gutless cars i hear you speak of

  • Reply Stephen Tutton August 14, 2019 at 6:41 pm

    You are dealing with large distances. Think of the old days with sail. Makes the vikings incredible. Want high speed ships use ground effect.

  • Reply Keang Stoneactivity August 14, 2019 at 11:11 pm


    Some random destroyer: Am i a joke to you?

  • Reply john russo August 15, 2019 at 12:46 am

    so…cause its heavy as hell

  • Reply Tim _ August 15, 2019 at 5:10 am

    Because they are way bigger than everybody thinks they are

  • Reply philip blake August 15, 2019 at 6:09 am

    So if drag slows ships down, then just delete drag or the ocean. So simple!!!

  • Reply Gaming War August 15, 2019 at 10:27 am

    I live in Southampton

  • Reply Richard Hopkins August 15, 2019 at 4:10 pm

    Terminal velocity only refers to an object in free fall.. Anything moving parallel to the surface of the earth, or that is being powered by anyting other than the earth's gravitational pull, does not have a terminal velocity

  • Reply Progressive August 15, 2019 at 4:14 pm

    lol 150, 000 hp ? Cute. The Saturn V rocket delivered 160,000,000 hp 😀

  • Reply GodsIlluminatedOne August 15, 2019 at 6:57 pm


  • Reply Dave Gab August 16, 2019 at 1:11 am

    Give the ship Engine a remap and boom 110 000 + Hp Easy 😂😂😂😂

  • Reply Dilan Judge August 16, 2019 at 3:34 am

    A typical car has a lot more than 100 hp.

  • Reply Bill Kong August 16, 2019 at 4:31 am

    Should have just went straight to wave drag.

  • Reply Bill Kong August 16, 2019 at 4:36 am


    It's not drag in the same way other things experience drag. When a boat goes fast enough the trough from its bow wave is at its stern and the ship is effectively climbing uphill at a steep angle. This practically limits the speed of all heavy ships. Boats that go faster than this do so by hydroplaning.

  • Reply Waxoff Waxon August 16, 2019 at 7:32 am

    This channel is really specific. But I like it.

  • Reply Redbug 3 August 16, 2019 at 1:27 pm

    It's because they are Fed up with it All and have decided to run the race they are running at their speed on the terms they choose!

  • Reply Pepe 358 August 16, 2019 at 6:28 pm

    You need a big brain to understand this

  • Reply D0ROGA August 16, 2019 at 6:43 pm

    Most stupid video about ships.

  • Reply Cindy Tepper August 16, 2019 at 7:36 pm

    My friend had a contract to cut up a container ship for scrap. It was in a slip in the Port Richmond section of Philadelphia. I was really surprised how easily it moved at low speed. He had to move it about 100 feet in the slip to secure it the way he wanted and pulled it with a 4 wheel drive Chevy pickup in 4 wheel low range. It really didn't strain at all

  • Reply Jon S August 16, 2019 at 8:57 pm

    100hp is typical for cars? My '84 Goldwing motorcycle puts out 99.

    No wonder I have such an easy time passing cars.

  • Reply Jon S August 16, 2019 at 9:08 pm

    The video mentions that cars deal with friction from the ground but neglects to mention that it's rolling friction rather than sliding friction. If the car experienced sliding friction–a closer analog to the fluid friction that ships deal with, it would be far slower. Imagine a car like a snowmobile, with skids instead where the non-drive wheels would normally be. I bet you wouldn't go much over 20 knots in that thing, either.

  • Reply ADHeroD August 16, 2019 at 10:17 pm

    sir we're currently going 750MPH, we have 32,000 tonnes of cargo on a 100,000 ton ship powered by a 32,000 ton engine and we're about 5 minutes away from harbour… shall I apply emergency breaks now so we can launch that cargo from here to the harbour?

    captain: I'm feeling lucky today I feel like we might get a bullshit on shore

    imagine that shipping containers being launched at us

  • Reply Mista Lahey August 17, 2019 at 6:58 am

    Fatass me

  • Reply Simon Skull August 17, 2019 at 11:04 am

    In planes you use pegasus power, off course you can't use horses!
    Seiya is the world's expert on this field!

  • Reply Drew Acabu August 17, 2019 at 1:48 pm

    Very physics

  • Reply Varun Jm August 17, 2019 at 5:48 pm


  • Reply Maximus 59 August 17, 2019 at 7:45 pm

    1:47 I didnt know that the horses are faster than planes

  • Reply abel adam August 18, 2019 at 12:26 am

    were is the train,, water is thicker and heavier the deeper the water the heavier,, the weight cargo and ships weight bring the ship down to the deep water,, the engines are running large and fast,the ship is slow for the reason mention above plus human safety and keeping product safe is a factor and avoiding collusions

  • Reply Omar Delawar August 18, 2019 at 7:28 am

    This was really awesome. I subbed! Much love from California!

  • Reply Marcus Davenport August 18, 2019 at 8:20 am

    Average horse power is 250-300 for cars.

  • Reply AJITH K UMMAN August 18, 2019 at 3:37 pm

    What happens if we fix jet engine on ship?

  • Reply mike henthorn August 18, 2019 at 3:50 pm

    Good video sir. You did this one thing about ship speed. The longer the hole at the waterline the faster the ship can go is the example of why the u.s. Battleship Iowa class is faster than the South Dakota class.

  • Reply L.Prawin Lukanus Santhanaraj. August 18, 2019 at 6:24 pm

    V ^2 is same for airplanes the drag equation is same. For ships the real factor is density which is 1000kg/m^3 or greater for sea water for air that is 1.225kg/m^3. You missed that point.

  • Reply Chevy Taripe August 18, 2019 at 7:48 pm

    why do seafarers and pilots use knots?

  • Reply Cozy Unbound August 18, 2019 at 8:32 pm

    Why don't they put use jet engines?

  • Reply Aceofthesky1 August 18, 2019 at 9:38 pm

    You couldve used a prop plane as a HP comparison (yes i know a prop is a lot slower than a jet, but it can cross the atlantic, though im not sure about the time)

  • Reply dogeness 🌹 August 18, 2019 at 11:58 pm

    Weight wouldn't be a factor in top speed though, right? It would only be a factor in acceleration.

  • Reply Alex Engler August 19, 2019 at 12:32 am

    Congratulations on your videos, most of them take me back to my days at the academy, and some of them are curiosities that I didn’t know.
    Keep up the good work.

  • Reply MykheL MykheL August 19, 2019 at 3:19 am

    + ships face more fish trafic and due to their large size and ships own large size it's hard for ships to maneuver around the fishes ???
    Need more & more fish proof sea lanes for ships – – – ???

  • Reply Trey Eden August 19, 2019 at 6:28 am

    Rpm and Torque has alot to do with this. Car engines and plane engines produce their power at a MUCH HIGHER rpm than the say 100 or so rpm that a ship engine will turn. They're also designed to turn high torque at low rpm to maintain fuel economy and experience less wear and tear. Horsepower is important when speed is the desired outcome, but a ship's designated occupation does not require speed, it requires more pushing force.

  • Reply DylanG_2K17 August 19, 2019 at 11:49 am

    Hey, at 1:17 the car is a citroen ds3!

  • Reply Paul Racine August 19, 2019 at 3:52 pm

    THEIR HUGE!! next!!

  • Reply Efren Magana August 19, 2019 at 9:21 pm

    What a stupid cuestión,

  • Reply Miguel Ellis August 20, 2019 at 7:29 am

    I know this is so obvious but the reason why ships have more horsepower then cars is because if a ship had a cars engine it wouldnt do crap, sitting there useless. But even so if you were to remove a ships engine say put it on something else way lighter, it wouldnt do crap either. It would be too heavy. In our world of modern technology people believe that horsepower spells everything speed. 100% false because take for an example an F1 car. Produces a ton of horsepower and its not street legal for a reason. Its to light for legal regulations. A standard F1 car only weighs 200-220 KG! thats super light for a car. Take for example a Bugatti Veyron. It produces more than an F1 car about 1200 horsepower. But the thing is, its heavy as hell. An F1 car would leave it in the dust. This also applies to motorbikes, a standard bike is extremely light but has an extremely low amount of horsepower. That doesnt matter it can still beat a car and go over 300 MPH. In the car world we havent even made a PRODUCTION car capable of that speed. (This comment is for all you nerds/car nerds like me out there)

  • Reply Ernie Minnette August 20, 2019 at 9:24 am

    Ships shouldn't be going any faster than they currently do. The Titanic would vouch for that.

  • Reply Joshua Hall a.k.a. Controlla August 20, 2019 at 10:50 am

    Great video.☺️

  • Reply BotoCorDeRosa August 20, 2019 at 5:20 pm

    Thanks for this! I love a detailed yet simple explanation.
    That’s when I know I’m listening to fact.
    It’s been 20 years since I last studied physics and it’s nice to not be patronised while having a short refresher. 👌🏽 10/10

  • Reply Nalleteus August 20, 2019 at 5:45 pm

    "Because ships use Diesel engine"

  • Reply reginaldo machado da silva August 21, 2019 at 11:52 am


  • Reply Delmus Ingle August 21, 2019 at 5:23 pm

    I would have liked a mention of water displacement as opposed to the weight of the ship and the weight of the water displaced.

  • Reply Leriw Nejzi August 21, 2019 at 7:14 pm

    I love your Videos (btw. I love to Fall asleep to them, your voice makes calm me down)

  • Reply Disappointed Prion August 21, 2019 at 8:41 pm

    This is naut true.

    Get it? Nautical? Naut? Ok, my jokes are bad, I'll just see myself out.

  • Reply William TheRailFan August 21, 2019 at 11:24 pm

    Of course, they would be even slower if it weren't for Parsons, and the creation of Turbinia!

  • Reply Kolby Brian2412 August 22, 2019 at 4:45 am

    It needs more Torque rather than horsepower because torque is how much you can over come the resistance forces and horsepower is how fast you can put out that amount of torque

  • Reply uncle dan August 23, 2019 at 9:10 pm

    no u.s.a. m.p.h. or other non-metric descriptions, NO WATCHY NO SUBSCRIPTION!!!!!

  • Reply Victor VonDoom August 24, 2019 at 4:22 pm

    This video kept constantly showing up in my recommended and I kept ignoring it because it was pretty obvious that ships are so slow because they're big and heavy. And then I finally broke and watched the video just to get it off my recommended list and discovered that ships are so slow because they're big and heavy. Time well spent…

  • Reply Eric Lalnunngila August 25, 2019 at 11:38 am

    Air is less dense… Thats all… This works for airplane road and watermeans…

  • Reply westyorkshire buses first leeds August 26, 2019 at 7:57 pm

    Send boat to building yard and get it steamedlined so where it can go at 69 mph

  • Reply Ingnorent Fish August 26, 2019 at 9:29 pm

    It’s like saying why is a lorry slow

  • Reply mandy mudfart August 26, 2019 at 11:37 pm

    because it's casual navigation NOT EXTREME NAVIGATION!

  • Reply barrel August 27, 2019 at 1:23 am

    would it be cheaper if you just tied a few thousand horses to a boat and made them swim

    can horses swim

  • Reply seasonedtoker August 27, 2019 at 7:08 pm

    It would take a lot of cars to haul what these Maersk ships haul

  • Reply Javier costa henere August 29, 2019 at 4:05 pm

    Could you make a video explaining the what's called "maximum hull displacement speed"?

  • Reply Bruce Dressel August 31, 2019 at 10:38 pm

    A car has 100 hp ?? ya maybe your car lol …

  • Reply High On September 4, 2019 at 3:16 pm

    Could you do a video about maritime logistics and/or port management? I love your channel!!!!!

  • Reply Tasty VeggieYt September 8, 2019 at 2:53 am

    Stupid question

  • Reply The Stoned Bear September 19, 2019 at 10:22 pm

    Well first you gotta find the weight of whatever vessel without cargo and then add the weight of the cargo so that will slow you down and cause even more drag two the current and the weather plays a major factor in making your travel time faster or slower if you go at the perfect time you can get a push from the current and go anywhere from couple knots to 10 or 12 knots faster (about 12 to 14 mph give or take) but you go against it then youll probably take a bit longer and if youre in a pass or a strait and with some of them if your against the tide youll move maybe 1 or 2 knots 3-5 if you know how to navigate close to the shoreline

  • Reply S B September 22, 2019 at 9:45 pm

    slow ? why dont you try to weight 100 ton and try swimming.

  • Reply Jackatsura September 24, 2019 at 8:29 pm


  • Reply Kieran Nicholls September 25, 2019 at 12:17 am

    Ships are big, heavy and have to travel through water…

    Hmm that didn't take seven minutes to explain…

  • Reply Lazar Hoe September 28, 2019 at 11:21 pm

    This baby got 350 llama Underneath the hood

  • Reply Bad Andy September 29, 2019 at 1:55 am

    Lots of drag? And most ships have female names? Guess you can say that ships are the original Drag Queens?

  • Reply phillip james September 29, 2019 at 11:18 am

    A lot of drag equivalent to a box shaped car in a wind tunnel and due to its width and length a body of water is very resistant!

  • Reply Titanic October 4, 2019 at 6:39 pm


  • Reply ωild τυrκεγ October 4, 2019 at 11:06 pm

    Ugh How is 33 MPH Slow??

  • Reply Drmcx October 10, 2019 at 12:21 pm

    Uhm because large heavy things are difficult to accelerate, slow down as well as maneuver?

  • Reply Will Joyce October 12, 2019 at 11:34 am

    because they are big

  • Reply Steve PH October 17, 2019 at 2:01 pm

    The Navy ships are fast reaching up to 30 to 35 knots

  • Reply John Barron October 20, 2019 at 2:08 am

    Why are swimmers so slow?

  • Reply Some Guy October 20, 2019 at 9:27 pm

    This just might be that I’m American but 100hp is week.
    In America cars usually have 400hp

  • Reply ErKa ScaZuchi October 22, 2019 at 3:57 pm

    because slow ships are romance while fast ships are porn

  • Reply Exolette October 28, 2019 at 12:45 pm

    Literally the comments section is just try-hard kids who just spitt out what they learned in science today.

  • Reply Edilberto Rivera October 28, 2019 at 9:46 pm

    Then how come a small boat can tow a battleship?

  • Reply Old-Style 86 October 29, 2019 at 2:00 am

    I got lost at horse power

  • Reply OnTheRoadAgain October 29, 2019 at 3:37 pm

    Emma Marsk has a cargo capacity of almost 7500 40 feet long containers with a weight of 21 tons each.
    This means you need 7500 18-wheelers to transport the same cargo. How many horsepower do you think they will have together?
    Not to talk about how many planes and their power….

    The largest cargo ships of today can transport 1 ton of cargo 1000 miles using only 1 gallons (or 1l/400km) of fuel oil.
    If you convert this to a truck, transporting 30 tons of cargo 100 miles would consume only 3 gallons (or 7l/100km) of diesel. I think the truck needs a little more fuel.
    So evem if big ships are slow, they're very fuel efficient.

  • Reply Sarah Winfrey November 4, 2019 at 12:30 pm

    brightside made a same video like this called the same thing you make it in may and he made it in 2019 im not sure if he is coppyrighting you

  • Reply Ieuan Hunt November 10, 2019 at 6:34 pm

    0:40 Cathedral engines eh? All hail the glory of the Omnissiah

  • Reply Sunil Kaflay November 10, 2019 at 7:20 pm

    Can you please make your subtitle a bit lower then screen so we can see your video clear some time subtitle make video covered sir …

  • Reply The Seawolf November 14, 2019 at 2:37 pm

    so stupid title….

  • Reply othername1000 November 15, 2019 at 12:08 am

    There is no s in math. There is no ne in tons

  • Reply Hiram Abiff November 15, 2019 at 7:04 pm


  • Reply Bob The Burger Builder November 16, 2019 at 4:39 pm

    So pretty much what most of us thought

  • Reply Robcop Westton November 16, 2019 at 5:10 pm

    Emma Maersk is 170000gt not 200000. even less as dwt

  • Reply Robcop Westton November 16, 2019 at 5:13 pm

    To go at speed of car or train or plane need a engine 1/8 of her size? more like 5000t. Ships are designed to carry a lot not for speed

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