Very, very good blending of photos, But I agree with Tamlin: it would work better if the third photo, the central one, was in front of the blue line. You have to find a way to match this photo with the other two, and in my opinion you have to make it stand out.... Three is a hard number, it's usually used to make one thing standing out through the other two elements. The human eye conforms automatically to this scheme, so why don't you just try to let those two photos as background for the other?
Maybe making them softer with a little blur and lowing the opacity will get some result