Hey HLS30,
The Midway has an armored deck so if you are trying to do damage with HE or AP she will bounce or shatter those shells (HE can still start a fire of course). Do you happen to have a replay so we can see the situation and maybe be able to give you some pointers on how to approach that situation the next time. A full health Hindenburg would take a CV some time to kill. Was the Midway backing up while you were going forward?
As other players have said, shoot the Midway under the deck and get yourself on the side of the Midway where you can do excellent damage with AP. You can also aim for the island that is on top of the deck but that is a smaller target when the Midway is bow on.
We look forward to you providing a replay if possible =).