Below you can see the front-view size comparison of the Olympus TG-4 and Kodak Astro AZ651. The Kodak Astro AZ651 is clearly the smaller of the two cameras. Its body is 112 mm narrower, 66 mm shorter and 31 mm thinner than the Olympus TG-4.
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.