Unable to swim up flowing water.

Put the summary of the bug you're having here: I was mining under water for sand and was trapped in the underwater hole I dug, unable to swim up.
*What I expected to happen was...:*swim up to the surface
Describe what you thought should happen here
*What actually happened was...:*I was stuck in the pit and drowned
Describe what happened here
I drowned
Steps to Reproduce:
1. Dig a 1x1x3 pit or deeper underwater
2. Try to go up
3. drown