![](https://www.historynet.com/wp-content/uploads/2022/04/The-Surcouf-scaled.jpeg)
The Surcouf, a massive 3,300-ton submarine, carried an observation floatplane in a closed hangar and sported
a sealed turret with two 8-inch naval guns. But the one-of-a-kind cruiser proved to be an ungainly escort ship. (Albert Harlingue/Getty Images)