Underwater Filters - for GoPro
Red Filters are used for Scuba Diving in Tropical or Bluewater. Below 10 feet of water, the wavelength of red light disappears. The camera white balance does not account for the loss of red light and videos turn very blue or green, lacking bright tropical colours. This red filter tricks the cameras 'brain' into capturing vibrant colours the way you see them underwater!
Snorkel Filters act in a similar way to Red Filters but are less Red, due to the fact that most snorkelling is done in shallow water.
Magenta Filters are designed for colour correction while scuba diving in green water.