New submitter home-electro.com writes "In the era of total CAD and CAM, is it even possible to come up with a fundamentally flawed design ? Turns out, yes. This a fascinating engineering SNAFU. Spain's newly built submarine is 100 tons too heavy, which means it is unable to float. 'Unfortunately for the Spainards, Quartz reports that they have already sunk the equivalent of $680 million into the Isaac Peral, and a total of $3 billion into the entire quartet of S-80 class submarines. If Spain hopes to salvage its submarines, it must either find some weight that can be trimmed from the current design or lengthen the ship to accommodate the excess weight, The Local notes. Though the latter option is more feasible, it is expected to cost Spain an extra $9.7 million per meter.'"