Dehydrated, ravenous, and seeing ghosts
All of their food supplies were lost at sea, and a swamp isn't exactly a suitable spot to go hunting. They were dehydrated, exhausted, hungry, and there was probably not much water to drink. Some people started having hallucinations since the situation was so awful. One of the guys “saw” a mess hall and started wandering out to find some food; luckily, someone woke him up just in time to prevent him from getting lost.