stuck on vertical level #1 - cannot jump!

I dug my way down to level 1. Now I find myself stuck - I cannot jump up, and there is no block above me. I went into creative mode, and I am still stuck - cannot fly! I tried to lay a water bucket and swim up, but no movement. I placed a stair block next to me, but i could not move to it (again, nothing above me).

Quit the game, saving it. reloaded and still stuck on lev. 1

Seems as if I'm going nowhere... help?