For underwater photography, choosing the right macro lens in the Micro Four Thirds system is key. The Olympus M.Zuiko ED 30mm f/3.5 Macro is compact and great for larger subjects but may spook shy marine life due to its short focus distance. The Olympus M.Zuiko ED 60mm f/2.8 Macro is a versatile option with excellent sharpness, making it ideal for a range of subjects. The OM System M.Zuiko ED 90mm f/3.5 IS PRO Macro offers the highest magnification and a longer focal length, allowing photographers to capture skittish creatures from a distance. Selecting lenses should depend on your typical underwater subjects and photography goals.