Wow, these make packing for a cruise (or any vacation for that matter) a cinch.  You can pack two pair and various snaps to give the appearance of a variety of shoe options.  I haven't experienced the frequent loss of snaps mentioned by some of the other reviewers.  So far, mine fit pretty snug.  Very pleased.  No complaints.

I look forward to trying a few pairs of Lindsay Phillips other footsy options.  I don't know how long these have been around, what a novel concept.  Glad I found them.  Thanks Amazon!