Other mistake: When the Political Officer reads the orders, they're supposed to test the silent drive and return home "on or about the 16th of this month." Shortly afterwards, Jack Ryan is briefing Jeffrey Pelt, and asks "isn't it the 23rd?", meaning the 16th of the month is in the past.
Other mistake: Even though Ryan was warned earlier that the water was so cold that you could survive in it for only four minutes, he doesn't even shiver while drinking coffee in his wet clothes inside the Dallas. This after plunging deep underwater from his fall from the helicopter and then waiting to be rescued and brought aboard by the diver.