Deliberate mistake: This mistake/trick was revealed in the second DVD commentary on the film. When Bond is underwater in the ship with the flare, this flare does not behave realistically. If they had used real flares, it would have put too much smoke and dirt in the water and quickly made it too murky to see or film through. So the flare used was a special effects prop of a bright light with bubbles being fed through it to give a good effect, but is not how a real flare would be under water. (01:08:25)