This solitaire game depicts the struggle between Allied convoy ONS.5 and a large number of German U-boats in May 1943. This struggle is considered a turning point in the Battle of Atlantic. The player tries to sink as many merchant ships as possible, the game system (rules and charts) governs the actions of the escort vessels. Sequence of play (as taken from the rulebook): Unit Availability Phase, Weather Phase, Convoy and Escort Movement Phase, U-boat Movement Phase, Search Phase, Combat Phase, Turn Record Phase The game is available at http://www.kcl.ac.uk/schools/sspp/ws/consim.html