(generally small, unpowered, one- or two-person submarines tethered to

Large subs are still built for the world's navies, a few smaller subsĭo work as scientific research vessels. Submarines are ingenious bits of engineeringĭesigned to carry people safely through this very harsh environment.Īlthough they were originally invented as military machines, and most It's dark and difficult to see, there's no air toīreathe, and intense water pressure makes everything feel uncomfortableĪnd claustrophobic. Where the water is calmer and puts up less resistance in practice, that creates a different set of problems.ĭiving, you'll know that life underwater is very different from In theory, it should be much easier for ships to swim under the waves Sailing ships make good use of winds, harnessing the gusts of air to make a very effective form of propulsion.ĭiesel-powered ships stay on the surface for a different reason: their engines needĪ steady supply of oxygen to burn fuel. Ships battle and lurch across tough seas where no fish-worth its salt-would ever swim. Racing from one side of the planet to the other. The sea are a sign of energy, originally transmitted by the Sun and whipped up into winds, Oceans are most turbulent where wind meets water: on their surface. Photo of USS City of Corpus Christi at Pearl Harbor Naval Shipyard by Dustan Longhini courtesy of In this very unusual picture of a submarine in dry dock for maintenance, you can clearly see how big a submarine really is-and that it really is almost a perfect cylinder. It's hard to imagine how big they really are: like icebergs, virtually all of a floating sub is underwater. Photo: Submarine ahoy! When we see photos of submarines floating on the surface,

First submarine