Overview

• Open-ocean tsunami swells measure only a few feet and pass under large vessels unnoticed when water exceeds 180 feet in depth
• Maritime authorities activated emergency protocols after the July 30 magnitude-8.8 earthquake off Russia, directing cruise ships away from coastal harbors
• Coastal tide gauges recorded wave heights up to 3.6 feet in California and a 30-foot water drawdown in Hawaii with no major damage reported
• A Norwegian Cruise Line vessel departed Hawaii so rapidly under warning sirens that over 300 passengers were left ashore
• Cruise operators rely on satellite monitoring, real-time alerts and crew training to execute rapid port departures and safeguard passengers