The application of the mandatory rules contained in Chapter XI-2 of the SOLAS Convention, known as the ISPS Code (adopted on the 12th of December 2002, in force since the 1st of July 2004), as well as of the Regulation of the European Parliament and of the Council (adopted on 31st of March 2004, in force since the 20th of May of the same year), towards the protection of the marine environment, constitutes a difficult challenge for those responsible for security. The main concern is the protection of the ship-port interface, and all procedures should be focused on creating a tight barrier to all past, present and future threats. This study offers a level of specialised knowledge on those subjects included in the security area, both regarding detection procedure methodologies for risks related to criminal human participation (identification of clues, signs, actions, behavioural patterns, responses to certain control stimuli, etc.) and from the ship standpoint as an independent, autonomous unit to control her integral safety. Contents are addressed taking into account the three main blocks that play a role in security: the ship, her types, structural design and transits; the port as a filter for the threats intending to reach the ship; and the individuals involved in both, besides the criminal elements causing the crisis.