Submarines are naturally expensive vessels to engineer; hence, utmost care should be observed when designing them. However, in 2013, the Spanish government spent $2.2 billion on a submarine that was too heavy to float. A slight decimal error in the calculations resulted in a vessel that weighed close to 70 tons. The government pumped in an additional $11.2 million, but the submarine was still unusable because its elongated size made it impossible to dock in Spanish ports.