It happened once to me, too. Well the game is not perfect so it may crash from time to time. Even odd, sometimes you are in the main interface and prepare for fighting, loading torpedoes, locking targets and BOOM, it crashes to desktop , no questions asked
The game was released early and had a lotta bugs when it shipped out. Even with the second patch, which unfortunately is the last official one (no more sub types DLCs as we all dreaming), or with the community help the game is not finished. It's playable and if you get lucky you may play for a while.