Continuity mistake: When the sub surfaces at Zebra it is shown running up a tower. When we next switch to a close-up there is no tower and it is running up an antenna.
Continuity mistake: Their first attempt to punch through the ice occurs in an area where the water depth is stated as 140 feet. After bouncing off the ice the sub submerges down below 200 feet and is still descending as it moves away.
Continuity mistake: When the nuclear sub Tigerfish submerges for the first time it is at dusk in rough seas. When they cut to an underwater shot looking up at the sub the water is very calm and light. Cut back to a surface shot of the tower submerging and it's once again dusk and rough seas.BocaDavie