Hey, buddy, can you spare a role?
I jotted it down in my Risk campaign book. I always used to do that so I could replay my moments of glory over a glass of brandy in the sleeping quarters. --Arnold J. Rimmer--
You mention scenario 4 (Volcano Island). There the Volcano tile is placed on nr 6 of the Island map.
But now I am confused. Should you only cover one island space? Only nr 6? So you should put both river terrain tiles on top of each other?
And another thing. Nr 6 on the Island map is not exactly the middle of the map. You should also pick nr 5 to be in the middle.
Nr 5 is more to the left of the map and nr 6 is more to the right of the map.
I'm sorry, I hadn't realized there were more than one River Terrain tiles. I focused on "Tile in the Middle of the Board" and where to place it.
So you would be correct - NR 5 & 6.