In this paper we have analyzed military and security requirements for surveillance. Using a data-set of wide swath SAR imagery for the English channel and high resolution SAR data for the Zeebrugge and Rotterdam harbour we have discussed if these requirements can be met by using this kind of data. The requirement to detect anomalous behaviour at open sea can be fulfilled for ships with sizes > 30 meter if appropriate context information is available. Displacement of not too small vessels and preparatory activities for illegal trafficking can often be detected in high resolution imagery. However, details and detection of replacements of these objects cannot be obtained.