In the context of maritime surveillance, low-power high-frequency surface-wave (HFSW) radars are attracting significant attention as cost-effective tools for long-range ship detection and tracking applications. In this paper, multi-target tracking and data fusion techniques are applied to live-recorded data from a network of three oceanographic HFSW radars installed on the coast of the German Bight, in the North Sea. This campaign follows a previous one conducted in 2009, in which two HFSW radars were deployed on the coast of the Ligurian Sea, in the Mediterranean. Ship reports from the automatic identification system, recorded from a number of coastal stations, are exploited as ground truth information. A methodology is then applied to classify the fused tracks and to estimate single-sensor and data fusion performances. Both in situ and model data are used to investigate the capabilities of the systems according to the variations of the meteorological and oceanographic conditions. Finally, preliminary results are presented and discussed, together with outlines for future works.