I've seen a couple of times on this forum about mysterious crashes around Dunkirk on more than one occasion.
It's funny-I've broke every rule in the book about saving close to land, close to ships, submerged and have never had a problem-knock on wood.
One bug I've come across that causes a crash a couple of times is moving your nav map around and getting Russia centered on screen. The game has crashed a couple of times I've done that.
Most crashes I've had earlly on were hardware related on my old rig. My power supply fan went out and my case had no case fan. I would get a CTD after about an hour of playing. After doing some RAM upgrades and the like, the little light came on finally-heat.

Installed a case fan, changed out the power supply, and blew the dust out of the case.
Voila!

No more CTD's.
I just had a recent problem with CTD's due to some mod conflicts due to installation order. I got that taken care of Friday and have actually been able to play some this weekend instead of pulling my hair out.