Since the Hadal zone is so deep under water (20,000ft - 36,000ft deep!), going there would require using a submarine that could withstand the immense pressures (more than 1000 times the atmospheric pressure we are used to) at those depths. I hope this helps!

Scientists have different opinions on how best to explore the Hadal Zone. Some, like oceanographer Sylvia Earle, believe that sending manned submersibles is the best way to understand the deepest parts of the ocean. Others think that autonomous underwater robots, are more suitable, arguing that these unmanned submersibles can collect much more data. In either case, though, designing vehicles meant for exploring the Hadal Zone presents some enormous engineering challenges!