Hello captains!

Now I have two choices, one of them are probably more correct.
I`m on a mission all the way to east coast of South Africa and the mission is finished so now the long way back home. But on the trip south I got five or six messages that my flotilla should go to west-coast of Madagascar for refuelling and repairs by a ship and move on to the arabian sea for patrol.
What happens with my current mission if I do so? and my map only have the grid-pattern in the Atlantic. Have some of you done this before?