Diamonds, like all other products, have been given to man to utilize and create jobs. If you are not into the romantic side of these blingy bits, consider that they are also very useful in industry because of their hardness and strength.
I found these lovely colourful diamond trawlers at Lambert's Bay, the best area for maritime diamond mining. This industry has only been commercially viable since the 1990's. Seabed crawlers can be remote controlled but mostly divers are needed. These divers, who can only work about six days per month because of our famous stormy waters, have to work in the cold of the Atlantic Ocean for up to 8 hours. When they spot diamond-bearing gravel on the seabed they direct the suction hoses towards it.
The gravel is then pumped onto sorting tables. When the boats return, the diamonds are taken ashore. What I loved about this scene was the hollow hoses floating on top of the water, providing seating for hundreds of Cape Cormorants.