This partner verb activity gives students a chance to practice speaking and conjugating in a non-threatening manner. If used sparingly in the classroom, the students will enjoy this "once-a-month" activity. If overused, I've discovered that they get bored and tend to grumble. Often, the students will compete against the same partner throughout the year, keeping track of who wins.
Feel free to change the subjects at the top of the Battleship board, or even the verbs in the left margin. I enjoy putting in student names from the class, just to keep it interesting!