I buy Bonine (or the generic meclizine) and it works great for us. It isn't available in Canada, but we live close to the border so we can go across and get it in any US pharmacy. Very reasonably priced. We also have ordered it online for Amazon.com. (not .ca) The other option is to buy it on the ship - we have seen it many times in the on board shop.
We used the patches once and hated them. Awful dry mouth and just a funny feeling overall.