Iron and Fire

This requires one of two things–>money to purchase ship miniatures -OR- time, which can be used to xerox/create ship silhouettes. For a classroom budget, silhouettes are probably more efficient, and students could even be assigned creating the silhouettes, researching ships, etc. before playing. For an added twist, anyone who has a ship sunk has to have their assignment torn up! This recreates hesitation at throwing ships in to battle willy-nilly and creates a very realistic hesitation.

Days of Decision

First edition tends to be directly tied with the World in Flames boardgame (making it harder to implement). This gives a good overview of the buildup to war, but requires some tinkering for classroom use.