A Cartographic Analysis of the 1939-1945 U-Boat Campaign

The 1939-1945 U-Boat campaign was inherently a geographic puzzle.The geographic extent of U-Boat operations stretched across the world's oceans and seas.Despite this spatial extent, most U-Boat books present the campaign in chronological terms relying on text to convey that history.If maps are included, they are few in number, not well designed, and univariate.Thus, maps are relegated to a supporting role.Surprisingly, a cartographic perspective on examining this puzzle is missing.To fill this gap, this presentation argues that a cartographic analysis of the U-Boat campaign through data-driven and map-based evidence is needed to better visualize and understand this campaign's geographic puzzle.Geospatial data on the U-Boat campaign is published by Rohwer (1983), Kemp (1997), andNiestl (1998).In these sources, records of each Allied vessel or U-Boat sunk include various attributes and coordinates.Visualizing this loss data using methods such as small multiple, mapping attributes, and bivariate/multivariate symbolization presents insights into the U-Boat campaign in ways not previously provided by U-Boat books.By applying these and other cartographic methods, the reader can begin to piece together this campaign's geographic puzzle by making inquiries into the why, where, and what of the geospatial data.A small multiple can show the change in a variable over time or space.For instance, a small multiple can show the changing locations of Allied vessels sunk or damaged by U-Boat types for a given time-period.Doing so reveals clues that help explain why patterns in the sinkings appear as clustered or dispersed.For instance, between 1 September and 31 December 1939, Allied vessels sunk or damaged by Type IIA, IIB, and IIC series U-Boats were clustered in the Skagerrak Strait and the eastern coast of the British Isles.During that same time-period, successful attacks on Allied shipping by Type VIIA, VIIB, and IXA series U-Boats were dispersed in areas west of the Bay of Biscay and the Iberian Peninsula, respectively.The patterns reflected on this small multiple encourage readers to ask questions about why these patterns exist.