Carnival Freedom question

[Aidansmommy2]

We'll be cruising on the Freedom in 3 1/2 weeks and i'm wondering if anyone can answer this question for me... our 3 yr old ds will be cruising with us and he'll be sleeping on the couch that converts to a single bed. He uses a bedrail at home on his bed and i'd like to bring it with us, but my question is, is there a way to get a bedrail under the cushions on these couches/beds? I'd hate to lug the darn thing if it can't be used. I'm guessing that the cushions are connected and that I won't be able to slide the part of the rail that goes under the mattress anywhere (can't think what those things are called:o ). If we can't use the rail, i'm thinking I can move a chair or something next to the bed to keep him from falling off. If anyone has any other ideas please post them, i'd be appreciative of any help.