Many great ideas fail at first, and for a long time, because they’re massively ahead of their time. The helicopter, airplane, submarine, gun, and many more are fine examples. The submarine though has literally hundreds (or thousands if you stretch the definition) of years of abject failure before about a hundred years of resounding success.
That’s a long time to be essentially sending people to a watery grave (with a few limited successes) before materials and engineering technology caught up to the vision of submersibles.
https://en.m.wikipedia.org/wiki/History_of_submarines
That’s a long time to be essentially sending people to a watery grave (with a few limited successes) before materials and engineering technology caught up to the vision of submersibles.