San Francisco -- Wander through the show floor of Macworld Expo and sometimes something strange or cool will catch your eye. The iPod submerged in water yet still playing qualified as this.

H2O Audio manufactures a line of iPod cases and headphones that allow the MP3 player to be used underwater at various depths. The cases are designed around various activities, some simply protecting the units against rough and tumble activities while others allow for full scuba diving depths.

H2O Audio's products are currently being sold online as well as through Apple's retail channel.

For the full product line, take a look here.