https://www.historyhit.com/facts-about-the-tiger-tank/
The first Tiger tanks could actually act as submarines. Each tank was fitted with a snorkel that would allow the tank to operate underwater as long as it could reach fresh air. This was intended to allow tanks to drive through deep rivers in Russia. Eventually the parts were dropped in favor of making the tanks easier to produce.
Modern tanks still use the idea
https://www.milweb.net/news.php?type...7&item_id=6921
Look at the second tank snorkle and gun barrel only showing
German Leopard 2 with extended cupola