Why the Zeebrugge raids were not wasted effort

Was the Zeebrugge raid a waste of resources?

No; it developed coastal-operation skills while pursuing the strategic goal of restricting German port access along the Low Countries coast.

The raids were more than failed attempts to close a port. They helped develop methods for coastal operations while trying to deny facilities to the Kaiserliche Marine. They also belonged to a wider British ambition to advance along the Belgian and Dutch coast, where naval gunfire could support the army and push German activity farther from the Channel. That coastal plan repeatedly competed with the coalition need to relieve pressure on the French at Verdun. Their value lay in operational learning and a larger frustrated strategy as well as the immediate attempt to block port access.