Actually that would be the easiest thing to provide since the ship merely needs to pump the ocean/sea water into the shower after it treats and filters it of course.
Buckets of salt water hauled aboard.
You have to go to the beach and swim in the salt water or take a shower in salt water and wash yor hair after.
It is because the fresh water has less density compared to that of salt water.
Salt water is more dense than fresh water. So when you're in salt water you float more than when you are in fresh water
Humans cam survive for about 3 days with out fresh water. Fresh water is brought on ships for this reason because distilling salt water on a ship is difficult.
Ships float in fresh water too. Only a little deeper, since fresh water is less dense than salt water.
Ships, boats, anything buoyant, really...
At the heads with buckets of salt water
water is the ground for ships ,and the salt water is the best conductor and it acts as a zero potential(like for us ground as) for ships.
Salt makes the water denser or heavier if you like. the result is that anything including ships will float more easily.
Because the the sea water contains salt, which increases the density of the water. Therefore, the ships becomes even less dense than the water, making it float higher.
your a dub butt if you belive in this stuff.