If you use countermeasures now and try to ascend afterwards, go here

From Create Your Own Story

The countermeasures are released quickly after acquisition. Ramius commands the ship to ascend to the surface and avoid the torpedo. It takes some while and emergency blows, but the scheme works! The Red October rises into the ocean and avoids the torpedo.

You find yourself close to the British warships that welcome you and offer you protection. You and the officers are able to defect to the west without problem. But the ship needs to go back because the Russians know it is not sunk, but not without you guys copying some valuable designs.

THE END