Where to trace the British water-protection story

What source traces how Admiral King learned about British use of water in ship protection?

The remembered source is Percy Noble's diaries and notes in the Churchill Archives, though publication elsewhere is uncertain.

The remembered source for Admiral King's discovery of British water protection is Percy Noble's diaries and notes in the Churchill Archives. Whether the account appears elsewhere is uncertain. Noble was a strategically and diplomatically minded admiral who served as Commander-in-Chief, Far East, in 1939. This is a useful archival lead rather than a complete published citation.