This is quite a fun tale of the first "Ironclad" naval battles of the American Civil War that pitched the "Merrimac" against the "Monitor". Despite the fact that much of it looks like it was filmed in a large swimming pool, the effects are actually quite good - lots of black smoke and painted ping-pong balls provide for some entertaining sea battle effects. There is a parallel melodrama of brothers forced to take sides, and young love plays in here somewhere too, but that's all just run-of-the mill "humanity" added into what is essentially a boys-own story of sea battles and clever inventions.