the third one's looking pretty good, but i don't think your reflection goes quite deep enough. from the base of the structure, make a reference point about a half an inch down, or wherever water level would be if you went in a straight line down through the ground, measure the distance from that point to the top of the structure, then flip the line over at the reference pont, and that will be the length of the reflection. also, you may want to put some suggestion of ripples as lighter colored lines. and depending on the turbulance of the water you may want to mix some sky colors with the board colors in the reflection.