The U-Boat Peril
- U-Boats using forward bases in France and Norway
- U-Boats begin hunting in 'wolf packs'
- Germans fight a tonnage war
The Convoy System, Depth Charges and Escorts
- Convoys are used to get ships safely across the Atlantic
- Protected by destroyers
- Depth charges, Asdic, hedgehog, radar and long range aircraft and carrier based aircraft all help cure the problem
The Mid-Atlantic Gap and How it is Closed
- Range of bombers increased
- Carrier based aircraft
- More warships
Summary
Germans fought what is known as a Tonnage War. This battle on the sea was one the battles that introduced many new ships and technological breakthroughs. The Asdic, Hedgehog, Radar, Long Range and Carrier-based Aircrafts were all present during this battle.