Pearson Edexcel · A-Level · History
Course version: 9HI0 · Version from Sept 2015
The changing nature of warfare, 1859–1991: perception and reality - 4 The…
Full specification wording
Paper 3, Option 37.1: The changing nature of warfare, 1859–1991: perception and reality - 4 The war at sea, 1917–45: the impact of submarines, air power and complex codes: The impact of submarines, 1939–45; Dönitz and the Battle of the Atlantic; the significance of May 1943 as a turning point. The importance of naval codes and associated technology: Enigma and counter measures.
Submarines in 1939–45 threatened Britain's Atlantic lifeline.
Checked against the Pearson Edexcel 9HI0 specification (opens in a new tab) on .
- Point 2 of 3
- 3 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
Submarines in 1939–45 threatened Britain's Atlantic lifeline. Dönitz's wolf-pack tactics, using surfaced night attacks and radio coordination, caused heavy losses. Allied convoys, escort carriers, Leigh lights, radar, Huff-Duff and long-range aircraft gradually closed the mid-Atlantic gap. May 1943 marked a turning point: U-boat losses rose sharply and Dönitz withdrew from the North Atlantic. Naval codes mattered: Enigma-encrypted messages, broken at Bletchley Park, gave convoy routing intelligence, while German counter measures such as stricter procedures and the four-rotor Enigma complicated decryption. The struggle shows how technology, tactics and intelligence interacted to decide the Battle of the Atlantic.
What earns the marks
- Explains Dönitz's wolf-pack tactics: coordinating U-boats by radio to attack convoys at night on the surface, exploiting weaknesses in early radar and escort cover.
- Assesses the impact of submarines on Britain's supply lines, including shipping losses, rationing and the strategic priority given to the Battle of the Atlantic.
- Evaluates May 1943 as a turning point: increased Allied escort carriers, very-long-range aircraft, improved radar and Leigh lights, and the breaking of U-boat codes led to unsustainable U-boat losses.
- Explains the importance of naval codes: Enigma-encrypted German signals and Allied decryption at Bletchley Park provided convoy routing and U-boat position intelligence.
- Analyses counter measures: German changes to Enigma procedures, the four-rotor Enigma, and Allied responses such as Huff-Duff and improved codebreaking techniques.
- Reaches a supported judgement on the relative significance of submarines, Dönitz's leadership, May 1943 and codes in shaping the war at sea.
Common mistakes and how to put them right
Treating May 1943 as the sole turning point without considering earlier convoy battles or later U-boat operations.
Put it right: Explain why May 1943 was decisive while acknowledging other factors.
Assuming Enigma was a single machine or that codebreaking alone won the battle.
Put it right: Show how Enigma intelligence was one factor among tactics, technology and air cover.
Confusing Dönitz's wolf-pack tactics with unrestricted submarine warfare of 1917.
Put it right: Distinguish the 1939–45 radio-coordinated pack attacks from earlier practices.
Describing counter measures vaguely without linking them to specific Allied or German actions.
Put it right: Name measures such as stricter Enigma procedures or Huff-Duff and explain their effect.
Exam tips
- Plan your answer around the three strands in the statement: submarine impact, Dönitz and the Battle of the Atlantic, and May 1943 as a turning point, plus codes and counter measures.
- Use precise evidence, such as convoy codes, specific dates or technological names, to support your argument rather than general statements.
- When discussing turning points, weigh May 1943 against other moments and reach a clear judgement about its significance.
- Link naval codes to the wider battle: explain how intelligence affected convoy routing and U-boat hunting, not just that Enigma was broken.
Try the lesson
The start of the Paper 3, Option 37.1: The changing nature of warfare, 1859–1991: perception and reality - 4 The war at sea, 1917–45: the impact of submarines, air power and complex codes: The impact of submarines, 1939–45; Dönitz and the Battle of the Atlantic; the significance of May 1943 as a turning point. The importance of naval codes and associated technology: Enigma and counter measures. lesson, made from checked teaching notes for this specification point.
Have a go first
Which German commander directed the U-boat campaign against Allied Atlantic convoys during the Second World War?
Listen
Submarines in 1939–45 threatened Britain's Atlantic lifeline. Dönitz's wolf-pack tactics, using surfaced night attacks and radio coordination, caused heavy losses. Allied convoys, escort carriers, Leigh lights, radar, Huff-Duff and long-range aircraft gradually closed the mid-Atlantic gap. May 1943 marked a turning point: U-boat losses rose sharply and Dönitz withdrew from the North Atlantic. Naval codes mattered: Enigma-encrypted messages, broken at Bletchley Park, gave convoy routing intelligence, while German counter measures such as stricter procedures and the four-rotor Enigma complicated decryption. The struggle shows how technology, tactics and intelligence interacted to decide the Battle of the Atlantic. A strong answer earns marks for these points. Explains Dönitz's wolf-pack tactics: coordinating U-boats by radio to attack convoys at night on the surface, exploiting weaknesses in early radar and escort cover. Assesses the impact of submarines on Britain's supply lines, including shipping losses, rationing and the strategic priority given to the Battle of the Atlantic. Evaluates May 1943 as a turning point: increased Allied escort carriers, very-long-range aircraft, improved radar and Leigh lights, and the breaking of U-boat codes led to unsustainable U-boat losses. Explains the importance of naval codes: Enigma-encrypted German signals and Allied decryption at Bletchley Park provided convoy routing and U-boat position intelligence. A common slip: Treating May 1943 as the sole turning point without considering earlier convoy battles or later U-boat operations. Instead, explain why May 1943 was decisive while acknowledging other factors. Exam tip: Plan your answer around the three strands in the statement: submarine impact, Dönitz and the Battle of the Atlantic, and May 1943 as a turning point, plus codes and counter measures.
Key words
Say what each word means before you turn the card.
wolf-pack tactics
Try answering aloud or in your head before turning the card.
May 1943
Try answering aloud or in your head before turning the card.
Huff-Duff
Try answering aloud or in your head before turning the card.
See every definition
- wolf-pack tactics
- Coordinating U-boats by radio to attack convoys at night on the surface, exploiting weaknesses in early radar and escort cover.
- May 1943
- A turning point when U-boat losses rose sharply and Dönitz withdrew from the North Atlantic.
- Huff-Duff
- An Allied response named among the counter measures in the struggle at sea.
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Test your understanding of Paper 3, Option 37.1: The changing nature of warfare, 1859–1991: perception and reality - 4 The war at sea, 1917–45: the impact of submarines, air power and complex codes: The impact of submarines, 1939–45; Dönitz and the Battle of the Atlantic; the significance of May 1943 as a turning point. The importance of naval codes and associated technology: Enigma and counter measures.
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