Unlike most compact cameras, you can attach waterproof converters and 45 mm lens filters to the TG series of cameras using the CLA-T01 lens conversion adapter. 

The Olympus FCON-T02 Fisheye Converter Lens provides the ability to shoot with a circular fisheye effect without sacrificing lens brightness. Simply change the zoom position of the FCON-T02 converter to switch between circular fisheye shooting and full-frame fisheye shooting. It features a waterproof finish for capturing images with unique photographic expression even underwater. The interior of the lens contains nitrogen to prevent internal fogging caused by temperature differences.