Fuze the lower you are the longer it takes for the ack to hit you.
At 100 feet of alt the ack will hit you roughly twice as far out as at 10 feet.
PLUS, the higher you are the lower your speed has to be for a good drop.
So you can come in faster on the deck and still get a good drop.
BTW a flat rudder turn is best for exiting, pulling up into a standard turn will get you killed most every time.
alamwuhk2a, yes it is for dropping torpedo's.
What I don't know is how close the pilots eye was to the gauge.
What speed the ship was moving at, or ideal speed for the plane.
LOTS of variables there.
Good luck on finding more specifics, hope you can read japanese.