In Minecraft Alpha Single Player Survival, what are the specifications to create a waterfall elevator to go from the bottom of a long mine shaft to the surface?
If I understand the theory, here's how you do it.
Remove the marked block and this happens:
To move up and down, swim up and down the column of water; move slightly out to breathe then continue your ascension.
This video shows, however, that you can also climb a boat elevator by simply swimming.
Here is a better design.
First, make a hole that is 3x3 wide and as deep as you want. At the bottom, add a block to the center, then dig out the sides:
The 1's except the center are possible exits. The numbers represent the number of blocks from the ground.
At the top, you have your hole:
Above it, place a wood balcony, at least 1 block between it and the pit:
then, place water on top of it (water will be B, W is wood)
It will flow down and make a perfect place to create a water elevator.
In order to use it, make a boat, place it on the middle block (at the bottom) and get into it(quickly).
To go down, just freefal but catch yourself in the water pillar near the end.
Note: the boat breaks each time when you do it this way, but boats are cheap, and it's easier to use.
Boats float in water. Essentially, all you need is a waterfall from ground level straight down from the top of your mine shaft to the bottom. Then, while at the bottom, boat your way into the waterfall and watch as you rocket to the top.