Question on Missions

[Akula]

Hello

I spoke to the officer in the bunker, this is for my first partol by the way, and he gave me a briefing to go to the east coast of the UK and sink merchant shipping there.

However after I finished the briefing, when I select start patrol, it says are you sure you want to start the patrol without a mission or something to that effect.

I continued on my merry way anyway, and when I contact Bdu via radio they say that I can return to base or keep on patrolling.

I have gone to the mission marker on the map, and haveing a miserable time sinking anything as I keep missing...but that is another story.

So, I managed to sink on merchant... but what do I need to do to accept the mission order? Or is this the normal way it goes? I have to sink 50000 tons before a certain date.. but if I haven't accepted the mission will the tally count?

Thanks for clarifying.
G