Rodney Bergquist was taking pictures top side with the lens hood on. When he went below decks he forgot to take the lens hood off. He started using flash and you can see the results, black spots on the images. He lighten one image with the dodge tool. Take this as a learning experience: do not use your lens hood with flash.

Tom Crews used the "Tungsten" White Balance setting on his camera for this special effect.

Tom Crews exposed the first photo using normal exposure which resulted in the outside being over exposed. The second photo was taken using "Exposure Lock" to set the exposure for the ouside which resulted in the inside passage being under exposed. By using "Exposure Lock" to set the exposure for the outside in conjuction with using the flash resulted in a photo that has the correct exposure for the inside passage as well as correctly exposing for the outside.