Battlestations: Pacific/1st Battle of Guadalcanal

Complete all the objectives to unlock the Iowa class battleship.

Find the Japanese Bombardment Force.
 * Primary Objective

Don't lose more than four ships.
 * Secondary Objective

Sink the Heiei within five minutes.
 * Hidden Objective

Secondary objective
Using your units cautiously and keeping them together can help you achieve this objective.

Hidden objective
When you get reinforcements, the Heiei will show up right behind them soon after. Both of your ships have torpedoes, so switch to both of them and use the torpedoes on the Heiei. Nothing else really works, because it is much more powerful than both of your ships. A few good hits should sink it. If you do this within five minutes you will have completed the hidden objective. Even if you fail this objective, it still becomes a primary objective, so you're going to have to sink it one way or another.