My caption for the image is
"The beauty in the deep"
The aquatic world is filled with numerous Beautiful Creatures - living organisms and minerals. Many of these discoveries have been made by man but there exists even more that are yet to be discovered. Man, (scientists especially) make finding regularly and that's what the picture depicts with the arms of three different people in the picture, reaching out to explore the beauty beneath.
Some of these beautiful aquatic animals include the Torquaratorid hemichordate, the Basket Star, the Dumbo Octopus, the Marrus Orthocanna and so on.
Minerals under water also include chromium, titanium, salt deposits and so on.
All these, man strives to discover, for the use of mankind.