From LEGO Batman Wiki
|User||Robin and Nightwing|
|Powers and Abilities||Underwater breathing/manipulating.|
The Water Suit is a suit upgrade for Robin and Nightwing unlocked in the eighth level of the game. This allows them to dive in deep water all the way to the bottom. It has an unlimited air supply and built-in flippers to swim, to resurface just hold jump. it is a regular suit with flippers an air-tank and a sea mask
With upgrades this suit changes from a regular batarangs to a batarang coated with ice that freezes foes on impact (not bosses).