I couldn’t resist this one.

One of Spain’s largest defense splurges may also be one of its most embarrassing. After spending nearly one-third of a $3 billion budget to build four of the world’s most advanced submarines, the project’s engineers have run into a problem: the submarines are so heavy that they would sink to the bottom of the ocean.

Miscalculations by engineers at Navantia, the construction company contracted to built the S-80 submarine fleet, have produced submarines that are each as much as 100 tonnes (110 US tonnes) too heavy. The excess weight sounds paltry compared to the 2,000-plus tonnes (2,205 US tonnes) that each submarine weighs, but it’s more than enough to send the submarines straight to the ocean’s floor.

Given the mistake, Spain is going to have to choose between two costly fixes: slimming the submarines down, or elongating them to compensate for the extra fat. All signs point to the latter, which will be anything but a breeze—adding length will still require redesigning the entire vessel. And more money on top of the $680 million already spent.

Why does Spain need submarines to begin with?