Excellent work - thanks for sharing. Shots like these makes you appreciate just how quickly and easily Nodal Ninja can be setup.
There have been other underwater 360 panoramas and they are always fun to view. If you are using Nodal Ninja underwater (not recommended and may void your warranty) I would suggest spraying or applying a very light coating of oil first on all parts being submerged. Afterwards be sure to take extra care to clean it thoroughly and recoat with oil wiping off all excess residue. Any water, especially salt water, is very abusive to anodized aluminum and will tend to create rust pitting in a short period of time. There are areas very difficult to reach for cleaning like the ball bearing components.
If doing underwater panos you should consider two pano heads and use one exclusively for this harsh environment. This way you can replace parts and repair as needed. We'll work with you on replacement parts as best we can.