The cogs, which are Irr Shp (S) in game terms, have got to be among the most expensive per AP unit existing. (Except for baggage which runs into that nasty divide-by-zero problem.) These are Essex Miniatures ships (item BOAT4). They cost about 20 USD each for a 4 AP unit, but they do look lovely. (Essex did a stunning job painting their example.) My sails were made by dipping facial tissue in a mixture of white glue and water. I think I fielded them once, just to say that I did. The difficulties in getting a waterway down in the first place and not being so unlucky as to get calm winds so that they move as in difficult terrain make them a dicey expenditure of 12 AP for the three ship complement.