Why Are Cruise Ship Pools So Small?

why is it that on a sunny sea day on a cruise ship literally thousands of passengers will try to cram around a tiny pool you'd have thought the cruise lines would have Realize by now that most people will want to congregate around a swimming pool on holiday yet they still insist on fitting one that's minuscule especially when you consider that thousands of people are probably going to want to use it so what's going on why are the swimming pools on cruise ships so small cruise ships as we know them are actually a relatively modern invention

they evolved when commercial Aviation rendered the old ocean liners obsolete practically overnight demand for passenger Transportation by sea plummeted so the liner companies were forced to adapt their business model attracting people that were wanting to travel for pleasure rather than purely as a way of getting from A to B those liners may have had the odd indoor pool for first class passengers to relax while crossing the cold Waters of the North Atlantic but when they evolved into cruise ships suddenly it was a different story with The Disappearance of the class system everyone had equal access

to the open deck areas which proved particularly attractive as ships began cruising to hot exotic locations operators soon realized that in order to run a successful business they needed to make the onboard experience more pleasurable than their competition and what better way than by adding luxurious swimming pools on the open decks to let overheating passengers keep cool the pools needed to be on the open deck because not only is that where there is the most open space but also that is where the passengers will want to use them ready for a quick plunge after basking

in the Sun so that's great surely you can just fit a couple of big pools surrounded by loungers and everyone would be happy well almost everyone you see the water and swimming pools has a couple of annoying characteristics when it's on a ship it's heavy it sloshes and it's incredibly expensive one of the cheapest ways to get fresh water is debunker from a Shor side connection and at the time of making this video you'd be looking around 350 per ton somewhere like Miami plus connection fees of course a hypothetical Olympic siiz pul would therefore cost

at least $99,000 in water costs a each time you wanted to refill it and of course you would also need to have the 22,000 tons of water stored somewhere on the ship just in case you get that dreaded announcement over the tanoi attention ships company Code Brown Code Brown liod deck midships usually you can fix a Code Brown with chemicals but occasionally it will involve emptying and refilling the pool instead anyway if we consider that an Olympic pool contains around 2 and 1 half th000 tons of water it leads us straight onto the next issue

water is incredibly heavy the super of a modern ship is usually designed to weigh less the higher up you go simply because it doesn't need the additional strength as you get higher up as there's less ship to support up there the addition of a large swimming pool not only means that you need to support that weight of water but you also have the additional weight of the stronger superstructure that's needed for the pool the KnockOn consequence is that a naturally heavier ship will have less spare capacity for other things such as fuel drinking water stores

and ultimately passengers at the end of the day it's the passengers that earn your ship ship Revenue so taking up all your ship's weight capacity with facilities may be counterproductive of course the weight argument is compounded by the fact that it would be high up on the vessel hopefully it's fairly intuitive that a weight high up will make a ship less stable necessitating additional weight low down to act as a bit of a counterbalance that's easy enough as you can add a load of ballast but ballast doesn't earn you any money so there's no point

carrying loads as it would be at the expense of Passenger carrying capacity to make matters worse the static weight of water is actually the least of your worries a far more concern is the dynamic weight through a phenomenon known as the free surface effect let's take a hypothetical pool at the top of a ship and see what happens when you lean over obviously a load of it is going to flow out and ideally straight over the side that's actually one of the advantages of having pools on the open deck but look at what's left in

the pool you've now actually got a wedge of water with its Center gravity shifted towards the low side of the vessel effectively making the Leaning even worse than it was before the wider the pool the further out that wedge will be and the worse the effect you can counter it with additional balast down low in the ship factoring in the potential shift in the water but again it involves you adding more ballast potentially at the expense of fee paying passengers as you can see a large pool can quickly become a massive issue on a cruise

ship potentially needing significant quantities of balance to counter instead what the cruise lines do is they design the pools to be a bit of a compromise they'll be narrower in width to minimize the free surface effect when the ship is rolling lengthwise it isn't nearly as bad because ships are naturally stable that way anyway I mean have you ever heard of a ship capsizing bow first so a long narrow pool might work but it would still weigh a ridiculous amount and require a lot of strength up high in the superstructure unlikely justifying the structural compromises

required instead the best compromise seems to be a couple of small plunge style pools where the strength can be covered with minimal amount of extra superstructure and the deck design can split the ship up into different areas making each pool appear bigger than it really is in one sense it looks like there are only a few tiny pools on the upper deck but clever design can make them feel bigger without compromising too much on strength weight and stability having shallower areas out to the sides adds a lot of space for paddling and children to play

without adding significantly to the depth crucially though when the ship heals over the free surface effect in these pools isn't that different to a single narrow pool in the middle of the ship the greatest wedge of water is retained near to the center line while a much shallower wedge is formed further rout if you need a deeper pool maybe for acrobatics or something again we can think carefully about where it could be designed you want to restrict the overall size to minimize the weight and restrict the width in particular to minimize the free surface effect

you also want to place it as low down in the ship as you can to minimize the increase in the ship's center of gravity due to the pool so somewhere like the stern is ideal compared to the upper deck pools it can be so much lower down yet still exposed to the Sun as you can see there's an awful lot that goes into the design of pools on a cruise ship so although it looks like they've just chucked a couple of little pools on as a bit of an afterthought in reality there's been a tremendous

amount of thought and consideration that's gone into the design as always I'd just like to end the video by thanking our plus supporters on patreon your continued support helps to keep these videos freeo view across social media so thank you for anyone considering lending your support plus supporters gain Early Access to add free versions of all our videos as well as Early Access to video scripts and the ability to vote for upcoming topics check out the link in the description if you'd like to find out more