The Manual is a codification of customary international law, an integration of existing legal standards for naval conflict with the Geneva Conventions of 1949 and Protocol I of 1977.
[4] The Manual is broken into six parts that each discuss a different section of the law, these being: The San Remo Manual was cited by the Israeli government to justify its boarding and seizure of ships trying to break the Gaza blockade (see Legal assessments of the Gaza flotilla raid),[5] as well as by the United Nations Human Rights Council's international fact-finding mission to support their finding that the seizure was illegal.
[6] In 2011 the UN-Secretary-General's Panel of Inquiry came to the conclusion that the Gaza blockade had been "imposed as a legitimate security measure", and that the flotilla should not have acted in a way that escalated the potential for conflict.
Paragraph 67 of the Manual states that belligerents may attack merchant vessels flying the flag of neutral states outside of neutral waters if they "are believed on reasonable grounds to be carrying contraband or breaching a blockade, and if after prior warning they intentionally and clearly refuse to stop, or intentionally and clearly resist visit, search or capture".
Further, while article 102 of the San Remo Manual states that a blockade is prohibited if it has the sole purpose of starving the civilian population or denying it other objects essential for its survival, the Inquiry panel found that there was a legitimate military objective (to prevent the influx of weapons).