As of 2015, there are no Otter Box cases for the Samsung Galaxy that are waterproof. The strongest case available is the Defender series, which features three levels of protection against dust, drops and scratches, but does not offer any water protection.
The Defender series ranges from $49.99 to $59.99 as of 2015 and is made up of three pieces that work together to protect the phone. The front of the phone is protected by a thin clear screen, which keeps it from becoming scratched. Each connection port also has a rubber cover, which prevents dust from interrupting the connections. The last piece is made from a thicker rubber and prevents cracks from occurring during drops.