Okay, so imagine you're on a big, huge boat in the middle of the ocean. You need something really important, like gold or silver, and you know it's somewhere down in the ocean deep.
The admiralty mining establishment is a special group of people who have the job of finding and getting these valuable things from the ocean. They have special equipment like big machines that dig deep into the seabed and underwater robots to find what they are looking for.
Once they find the treasure, they use other special boats or even helicopters to collect it from the ocean and bring it back to the surface. The admiralty mining establishment is really important because it helps us find and use things that can make our lives better, like money or precious metals.