Question: Why did Cmdr. Gifford (John Wayne) give Ens.Caldwell a bad look when he said it was the first time he had seen a sub knocked off?
Question: Why do they look into the scope soon as it starts to rise? The view part would still be in the water.
Answer: A good submarine skipper ensure he always has a low periscope profile, as it's easily seen when out of the water too much. That's why he looks through the scope even while underwater, so the scope is only just out of the water.
stiiggy