Why K-class submarines made poor fleet scouts

A submarine's core strength is concealment for an ambush. A fleet scout instead had to remain on the surface, keep pace with battleships, detect enemy units at useful range, and coordinate its reporting. Contemporary diesels could not provide the required power, so the K class used steam turbines whose smoke and steam arrangements imposed severe operating penalties. Limited periscopes and hydrophones made the boat a poor observer, while a hull optimized for surface speed handled badly underwater. Coordination introduced another danger because friendly surface ships that saw a large, unfamiliar submarine silhouette often tried to ram it. Providing targeting information for a battle fleet was a different requirement from the modern SSN role raised in the exchange. Coordinating submerged submarines with surface ships remains difficult even with much later technology.