Below you can see the front view size comparison of Ricoh WG-30W and Pentax WG-3. Ricoh WG-30W is clearly the smaller of the two cameras. Its body is 1mm narrower, 2mm shorter and 3mm thinner than Pentax WG-3.
Ricoh WG-30W vs Pentax WG-3 - Front View
Ricoh WG-30W vs Pentax WG-3 - Top View
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.
Camera Size Comparison
Select Two Cameras for Size Comparison