Go to a place where is water, and then with the bucket on your hand, press and hold to a water block, and you will break the water block, the hardness is the same as the bedrock
MCPE-3857
Empty buckets can destroy water blocks (Survival and Creative)
Resolved
Fixed
1
(Unassigned)
Unconfirmed
Tablet - iOS - iPod Touch 5
0.7.0, 0.7.1, 0.7.2, 0.7.3
0.7.4
Retrieved
Just saying, you can break water with the bucket even if you are in survival mode. Just be persistant. Takes about ~5 minutes (real time).