Ghost Pirates of the Sea-erra Madre

You squeeze into your tight sea suit and then enter the Seeker 3. It has all of the latest technologies in undersea exploration: radar, radio, a special
laser light that can be used three times, air tanks, a harpoon launcher, and probably some other stuff.

You begin the long descent into the water. As time passes you see a plethora of strange sea creatures outside the windows of the Seeker 3. But you can't stop to take a look at them now, you've got to find Atlantis!

Just as you reach a raised ledge near the seafloor the tether attaching your submarine to the ship on the surface reaches it's limit.