https://centerformaritimestrategy.org/publications/the-next-pearl-harbor-the-threat-of-modern-drones-to-americas-pier-side-fleet/
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The threat to American warships in port, however, remains significant. The Navy primarily designed its current security infrastructure to prevent surface attacks, including those involving waterborne improvised explosive devices. Installed in part after al-Qaeda's suicide bombing of the USS Cole in 2000, this infrastructure includes harbor patrol craft, waterline security lights, and port security barriers. These security elements may stop an unmanned surface vessel; nevertheless, they will not impede a UAS flying at an altitude of 100 feet. .."
