I recently returned from a diving trip to Belize. The diving was great, but the UW Photography conditions were less than ideal. Most days were overcast, and none of the visibility was outstanding. In the famous Blue Hole, the water was full of particles making it particularly challenging. Not a lot of macro subjects either. As a result I used my single strobe on almost every shot.
This resulted in all kinds of backscatter of all different types. Circular blobs, squiggly lines, bright points, and blown out highlights showed up in a lot of the pictures. I even got some backscatter on shots taken while snorkeling without a strobe. After color correcting the RAW files, the backscatter became even more evident in some of the pictures.
Fortunately these images prove to be a great testing ground for BackShatter, and have helped me improve it to handle more of the cases where backscatter shows up on your photos.
Check out the Belize gallery for some examples of how BackShatter can fix the backscatter in your UW photos.