Where do I actually find Winstons Specials

I have reached the Winstons Specials stage.
I have followed the red route line,searched 200KM's either side in a grid search reached the Cape Verdi islands & have searched a 500KM diameter area from north to south going anti clockwise from July 5 1941-August 28th 1941 and still cannot find the 5 troop ships.

Has anybody actually found these ships & if you have,please tell me where & when you found them.

Thanks in advance