Visible crew/equipment: When Captain Dodge is sitting down to talk to Lake, you see the boom mic follow him down. (00:56:10)
Visible crew/equipment: When Dodge Say's "Good ole Graham" you can see the mic on top of the screen. (00:14:50)
Visible crew/equipment: When Stapanak is running to the engine room, the camera equipment at the bottom of the screen is visible. (01:11:45)
Visible crew/equipment: When Howard is starting the engine, he's stepping over the dolly track for the camera rig. (00:23:05)
Visible crew/equipment: When the Stingray is shown going out of the harbor, the blades of the chopper shooting the aerial shots can be seen in the upper right corner of the screen.
Answer: Adding alcohol to gasoline can lower the fuel's viscosity, thinning it to flow more easily. It can only marginally increase an engine's speed and power.
raywest ★
But the question was, would it have actually increased the sub's speed?
Thinning the fuel mix would not increase energy or performance, so it would not make the submarine faster.
Technically, yes, diesel with alcohol burns better. As for what happened in the movie: no. Whiskey is not alcohol; it's water with alcohol, and the water reduces the flammability a lot. Also, a sub has fuel tanks that hold tens of thousands of gallons; adding a few ounces of whiskey will not have any effect at all.