Here We Go!

We're going down now. The pilot has filled the ballast tanks with water to speed our descent. Because our submersible is pressurized, we'll have no real sensation of movement unless we look out the small portholes. It will get dark quickly as we descend. Sunlight doesn't penetrate well below about 305 meters (1000 feet). At 1500 meters (1600 feet), sunlight's intensity is one-millionth of its surface intensity. We'll be down at 2222 meters (7290 feet).

Occasionally we'll see bioluminescent creatures out the small windows. Inside, we'll work by the glow of the instruments and TV monitors and use our flashlights so we don't spoil our view of the dark, watery world outside. We'll have a strobe light to find our way around the ocean's floor. Our top speed will be 3.2 km (2 miles) per hour on the floor itself.

Throughout our mission we will hear the sounds of our submersible: tracking pulses every five seconds, navigational signals sent out and answered every 15 seconds, the machinery at work, oxygen entering the sphere, and carbon dioxide being removed. To learn more about the acoustic underwater navigation system, please check the Sound portion of our InterActivities page.

When our altimeter tells us we are about 91 meters (300 feet) from the bottom, we will drop half of the craft's 454 kg (1000 lb) of steel weight ballast to slow our descent. The pilot is watching out for mountains, caves and fissures that might trap us. We're on the ocean floor right now. By letting out some water ballast, the pilot brings the submersible to neutral buoyancy. The outside lights are turned on. We can see lava that looks like puffy pillows.

The pillow lava.
Photo courtesy of NOAA.