  We describe how specialized database technology and data analysis methods
were applied by the Swedish defense to help deal with the violation of Swedish
marine territory by foreign submarine intruders during the Eighties and early
Nineties. Among several approaches tried some yielded interesting information,
although most of the key questions remain unanswered. We conclude with a survey
of belief-function- and genetic-algorithm-based methods which were proposed to
support interpretation of intelligence reports and prediction of future
submarine positions, respectively.
