Use the Blue Water Filter with natural sunlight in shallow blue-green tropical fresh and salt water. The filter is designed to bring out the colors underwater from slightly below the surface to approximately 24ft/8m. The maximum depth will depend on the amount of natural light and water clarity. The Blue Water Filter is ideal for Video and Still images. The filter is a wet mount which means you can take the filter off and put it on under water. Once you get to below 24ft/8m, you may need to take off the filter and turn on your lights to capture the colors. The filter can be snapped onto the large cap for storage during the dive or be snapped onto the front of the camera lens while underwater.