While we asked for bed rails on our last cruise, once we say how low the convertible sofa is, we opted to just skip them all together for our 2-1/2yo. Of course in his case, he's been sleeping on a regular bed since he was 16mo. We started with just a matrise on the floor. Of course those first few weeks, he fell out a few times. But since then we've added the box-spring under the matrice and havn't had any issues. Since the convertible sofa was barely higher than the matrice on boxsprings on floor, we skipped.