On the ship I was aboard, everyone from E-1 to E-6 slept in the same berthing area on racks stacked 3 high. 
@rangerrebew Well,on ships there is a limited amount of space available.
My only ship experience (other than being the only deckhand on my uncle's shrimp boat as a teen) was getting stuck with escorting a truck full of classified radio equipment back from the Dominican Republic to North Carolina after the rebels in the DR had been defeated.
I knew there was going to be problems when I drove the truck up to the LST ramp on the beach,and could see the rear of the hull twisting around,and the front ramp being stable on the beach. The LST was also serving as a troop carrier,and after securing the truck on the deck,I went below to check out the sleeping spaces (there were two of us to guard the truck),and the vomit was already covering the deck,not to mention all the vomit in the hammocks that were 3 or 4 high. Right then I decided my trip would be entirely on the upper deck,sleeping in the truck.
Luckily for me,not to mention the leaders of that poor leg unit trapped below decks,I,a high-ranking PFC after having been busted for a minor misunderstanding involving whiskey and MP's,didn't have any butthole over me demanding I had to remain below decks except for exercise times. I THINK they may have been allowed up on the deck in small groups at random times,but don't really remember.
So the trip wasn't that bad for me,except for when we hit that tropical depression and the LST started taking 30 degree + rolls. Even then,as bad as it was on the upper deck ,below decks had to have been a living hell. I was off radio watch so I was sleeping in the cab of the truck,and woke up stading on the driver's door and looking down at the ocean.
Didn't take me long to get the HELL out of that truck and find my way to the mess hall,which was open 24/7. Luckily for me,the sailors were friendly to GI's,so I spent the rest of that storm in the mess,drinking coffee and talking to the sailors.
