If by "collier" you mean a coal ship, I have heard that Schipperkes were originally barge dogs, so they might be a good choice for voyages on a ship.

If by "collier" you mean a coal miner, then I would imagine any dog that doesn't need a lot of exercise or activity, is fine staying home alone for long shifts, and is willing to do just whatever when the owner is able to be home with them, be it a rest on the couch or a romp at the park. Something laid back and calm, maybe a greyhound?

dictionary.reference.com

Gio answered on 9/26/08. Helpful? / 0