Thirty-five millimeter film is dead. Everyone over the age of nine now owns a three-megapixel digital camera with a 10X optical zoom. Parents upgrading to telescopic lenses are passing down their relics to kids who can’t aim and have never loaded a roll of film. In the digital revolution, the disposable camera was merely an innocent bystander (along with Polaroid). But at dive shops and drug stores, the single-use underwater film camera has survived as the practical option for honeymoon photography and pool party documentation. With the recent launch of the 5.0-megapixel Digital Underwater Camera Mask from Liquid Image ($99; a 3.1-megapixel version costs $79), the end is near. To see how potent the gadget could be, I spent an afternoon underwater attempting to document a most difficult subject matter: two kids under the age of seven.