Castelnuovo - I'm afraid that you don't know what you're talking about, let alone what I'M talking about. Ballast refers to anything that is taken on by a boat that needs to submerge in order to be unseen, and therefore "Stealthy". Since submarines are designed to be hollow they are full of air that can't be vacuumed out or the crew would die. The only way for the ship to submerge would be to take on more weight and the only way to do that is to have something that is quite heavy, available, and ready to be used at a moments' notice. This is of course the only thing that CAN be used, and that's the sea water around it. As the ships' ballast tanks fill with water this makes the entire ship sink downwards. This is controllable as the tanks can be filled and closed by controls at the seamens' control center where the Captain sits, and monitors his crew, and vessel.
In essence; the more water the deeper the vessel can go into the ocean as needed to evade the enemy around them. In a giant boat that is self-sufficient there's no need to add more water to it to make it heavier than it already is otherwise you'd have the first deck sink to the water line! There's no need for a desalination tank since these boats are filled with FRESH water when they leave port. Sure they have tanks for them, but the only fresh water used is for the showers, sinks, and drinking as well as the water the kitchens use. The toilets use the same type of sanitary system that airliners use - solid waste disposal units. The same with the used run-off from the sinks, showers, and kitchens. This is stored in tanks that are returned, and drained when the ship goes back to port. These cruises only last for one week, maybe two at the most. They aren't like aircraft carriers that can go to sea for months on end! Those are equipped to do so - not cruise ships. Another thing to consider: I had a 15' foot swimming pool that held 1,500 gallons of water. We used CLORINE to clean the pool with as this is the proper protocol when cleaning pools, and for maintaining their cleanliness.
It takes 8 HOURS to drain one of these through a one inch hole - imagine how long it would take to drain an olympic size swimming pool which holds about 660,000 gallons through a four inch hole! That's 5,280,000 LBS. of water to drain. No friend - they DON'T have an emergency protocol for emptying a swimming pool unless they're going to use it to put out a fire! Think about everything that I said - people, clothing, their belongings, the tables, chairs, equipment, carpeting, furnishings, tools, kitchen utensils, the kitchen staff, hotel staff, ships' crew, their belongings, clothing, tools, equipment, all the materials, and supplies that they keep on hand the ships brig - (yes there is a place for unruly customers), the infirmary, all their supplies, lighting for the whole ship and all its' wiring, glass, rubber, glue rivets, screws, wood, steel, aluminum (which is what is used to skin the upper decks now), fuel, as well as the engines themselves, the fuel inside them, the oil tanks, all that empty space means nothing!
The stabilizers are only five feet wide - that's not a lot of surface area to stabilize a boat of this size since there are only two on each side of the ship! It takes about two to three years just to refit one of these cruise liners. This is why cruise lines have more than one ship available so that they can keep making money if one of their fleet goes down. It's an astronomical figure to build one of these not to mention the five to ten years that it takes to plan, engineer, financially fund, and build one of these behemoth nightmares! Don't forget about the army of lawyers, and accountants, personal assistants, and secretaries that you'll need. The multitude of contractors, and goverment agencies that also get involved along with OSHA. There's a lot more to this than most people will ever know, or understand. A friend of mine and I were going to start our own cruise line funded by hotel casinos, and restauraunts - A HUGE MISTAKE!! It would've broken us both financially, and spiritually if we had gone through with it since the logistics of having to oversee so many employees, security staff, overhead bosses, as well as the money just to foot the bill for a new cruise liner, and hotel would've cost over $260,000,000 alone! Most of that for a new boat. Yes friends, there's a lot more that goes into this than you realise!
: ( <----- sad face
~ Cobra Chris