The "Po" is a 6mm ply board with adhesive blue tiles from Homebase on it. I am cautiously pleased with the tiles which are much more hard-wearing than my previous attempt at a river. On the downside, they needed to be cut down to size, which was a real pain, and one can see the joins to some extent. The separate banks are also 6mm ply, build up with 3 layers of 2mm MDF. They sit over the edge of the river, disguising the join between the boards, and are the same thickness as the 12mm MDF boards that I will be using with the game.
The river will also do service as the Rhine, for 70AD games, especially if I can make up some models like the Liburnian that Skull and Crown sent me. I am considering making another 4' length of river, and a couple of narrower rivers, too.
If you are coming to Partizan on Sunday, and would like to move a legion or so about, please drop me a line!