Over 3,000 years ago the Assyrians developed a remarkably advanced underwater technique, as illustrated in this ancient relief. It shows Assyrian soldiers using goatskin bags filled with air to breath
Yup It makes no sense from a materials perspective. How would they handcraft an air and water tight goat skin bag with a tube coming out of it? And what's the tube made of? And all this effort for what, 3 lungfuls of air.