The journey into the West by Elves leaving Middle-Earth was a one-way trip. Not a shuttle service.
That would imply that any nautical crews on the ships also weren't coming back.
However, floating the boats isn't a task for amateurs: you'd need to make sure that any trip had properly trained crews.
I had this silly image in my head where things go something like this:
Elrond: Avast, ye landlubbers!
Galadriel: ... what?
Elrond: Just lightening the mood. We're outta this here sad and sorry lands. Next stop: Tol Eressea. Now, everybody call me captain!
Gandalf: I've got your "captain" right here, boyo! Now, who knows how to steer one of these things? Cirdan gave me a ring, not a Boating for Dummies book.
Galadriel: Is this thing supposed to be taking on water?
Elrond: No idea, but we can always throw one of the hobbits overboard. They're really just ballast.
Bilbo and Frodo: ...
Who steered/crewed the Grey Ships and where did the crews come from seeing as it was, by definition, an attrition process?
Were they "magical", imbued with some pathfinding auto-pilot by Cirdan? Then, how did Legolas' ship work? He was a landlubber, from Mirkwood.
Did Cirdan keep training crews among those who had decided to leave, with just enough minimal personnel to get them safely into the West?
Was it just one of those "Elves instinctively know bloody everything"?