Here's my entry into the informal "2011 Boat Building Challenge" over on the Post Apoc Wargames forum:
In scale feet, the barge would be approx 65 ft long by 37.3 ft wide
Wood planking covers the hold, giving the occupants shelter and storage
A cabin, made from scraps of wood and metal affords topside shelter
Sandbags provide protection against marauders
A WIP thread can be found here, detailing how it was made and showing pre-paint photos. The sandbags are the only new edition since that thread and are from Acheson Creations. I plan on carrying this project over into 2012 by adding the following modular pieces; although I am not sure if it will stay on the Workbench list.
An armored watch tower
Goods and portage for the deck
An ACE ZU 23-2 kit
Another thing that occurred to me to do is to create a concrete levy in order to create a river bank/dock feature for my developing PA table.