Quote Originally Posted by TimUsher View Post
Tobirama was primarily known for his mastery of Water Release jutsu, being able to make use of powerful water jutsu in areas where there were no bodies of water. He could manipulate it to form projectiles or tentacles, and could even perform jutsu like the Water Release: Water Dragon Bullet Technique with only one hand seal (use of the jutsu normally requiring 44 hand seals).

Tobirama Senju - Narutopedia, the Naruto Wiki

Even better than I thought. :D