Within 60 seconds.
5 days
Most U-boats of WWII were physically capable of diving to maximum depths of around 150-160 feet, although they seldom ventured that deep unless in an emergency. They could attain this depth in approximately 60-65 seconds. Advanced designs in hull reinforcement, mainly pioneered by Germany made this possible. The modern military submarines of today have hull-crush depths of closer to 1,500 feet and that number is growing with advances in technology all the time. These kinds of depths take much longer to reach, depending on dive rate, but can take in the region of 20-45 minutes. (Exact figures are hard to come by, as such information is often classified) Some cutting-edge un-manned submersibles are capable of diving to depths in excess of three times this depth but dive much slower, as their engines are not as powerfull as those of a manned submarine.
2 hours
The deepest dive to the bottom of Atlantic ocean was 10,994 meters deep. It was done by Don Walsh in a submarine and the dive took 4 hours and 47 minutes.
It completely depends on the situation. If it were a completely general jump (falling on your belly at 120 MPH, and opening at 3,000 feet), freefall would last for 60 seconds. Changing your body position and deployment altitude and increase or decrease that time.
It will take around 17-19 hours of drive. The distance is around 1800 km depending on which route you take.
hi
Depends on how fast you're going. Not long though.
There is no minimum interval. A dive directly from 70 fsw for 29 minuts can immediately be followed to a dive to 50 fsw for 39 mins, and would be classed as a "Combined Dive" To calculate decompression from this Combined Dive, is by taking the depest depth, (70 fsw), and total time (68 mins), and decompress on an appropriate table. Using the USN repetitive dive times, this varies on the residual nitrogen remaining in solution.
depends
Most often, 30 foot dives will take place in open water. There are some dive training centers with dive pools that may be deep enough. If you are planning to free dive (hold your breath at surface, dive, and return), you can go out into open water and try some free diving, shallow at first. Do not do this without a swim/dive buddy. If you want to dive SCUBA, you'll need to get certified first to avoid killing yourself. When ascending after breathing air under pressure, you'll need to do it properly. Free dive or SCUBA dive, I would never recommend diving without a swim/dive buddy with you.
A long time...