The destroyers were assigned to protect Repulse from submarines during sensitive wartime speed trials off Arran. Their presence acknowledged that secrecy could fail and that even a new battlecruiser needed an anti-submarine screen. The smaller ships kept up while running with the wind but fell hopelessly behind when Repulse turned into a moderate sea. The trial exposed the difference between nominal speed and an escort's ability to keep station in real conditions.
Notable Point · 21:12-22:52
Repulse trials expose destroyer seakeeping limits
Destroyers assigned to guard Repulse during speed trials could keep pace downwind but fell behind when the battlecruiser turned into a moderate sea.