How complete patrol 7?
 

have problem in patrol 7, i must go to zone AN97 but when i arrive the game system don't recognize this, how pass this mission?
Another question is why in designated patrol sector is few ship to sunk, in preview mission i sunk four merchant ship but only one was sinked in my patrol zone.

Stock bug. I think I have seen cases where

• The game takes time to recognze that you have arrived. If so, just wait.
• The boundaries of the patrol area are inaccurate. If so, move closer to the centre of the area.
• The label on the whole grid zone on your map is different from what the game thinks you are in. If so, travel to all the adjacent grids to see if the game recognizes that you have arrived.

Most u-boats never sank anything. On some patrols you won't see anything. To maximize your chance of detecting ships, use frequent hydrophone searches at low speed and low time compression. See this thread for more details.

WELCOME ABOARD!:sunny:

Also it's not like a shooter game. You gain some extra renown for going to your patrol grid, and more for staying there for 24 hours, but it doesn't hurt you if you don't do those things. There is no punishment.

Same with the ships. The game doesn't care where you sink the ships - you get the renown for sinking them wherever it happens.