The passengers on the second ship the narrator encounters in Edgar Allan Poe’s “Ms. In a Bottle” are strange in three ways.
First, they are elderly. Generally, sailors are not very old, since the work is both physically strenuous and dangerous. Those who do not retire are likely to die relatively young.
Second, the passengers are strange because they cannot see the narrator. As the story progresses, the reader begins to realize that they are in fact ghosts. It is, however, quite strange that the narrator can see them, but they cannot see him.
Third, they are strange because they seem increasingly hopeful as they approach their own destruction. One might interpret this as looking forward to their final rest.