Naval tactical blunders from Glorious to the Armada

What are the greatest naval tactical blunders?

Examples include Glorious's weak escort, missed Japanese follow-on attacks at Pearl Harbor, and command and coordination failures at Trafalgar and in the Armada campaign.

HMS Glorious was allowed to sail home with only two destroyers despite known German surface ships and submarines in the area, while HMS Courageous was risked as a fleet carrier hunting U-boats. At Pearl Harbor, Japan declined additional waves that might have struck depleted defences and inflicted more damage, trading aircraft preservation for less strategic delay. Villeneuve took the Franco-Spanish fleet to sea as his replacement approached and then tried to withdraw after encountering Nelson. The answer also points to weak defensive preparation at Crete, Singapore, Malaya, and Norway, and to the Dutch delay that gave Duncan time to assemble before Camperdown. In the Armada campaign, inadequate communication with Parma left the fleet exposed at an unsuitable anchorage where fireships could exploit wind and position. Across the examples, the recurring failures are avoidable exposure, poor coordination, and surrendering operational freedom before battle begins.