DNV has reason to believe that vulnerability studies might reduce risks of unwanted delays.

DNV in Miami has for several months executed vulnerability studies of cruise vessels operating from Miami. Vulnerability in this context means the vessels ability to maintain its operating schedule and maintaining comfort services for passengers if a single electrical fault should occur.

The purpose of the study was to reveal weaknesses which could affect schedule keeping and passenger comfort, not basic safety covered by Class Certificates.

Incidents causing a two-hour delay or loss of black water service at sea for five hours could mean dissatisfied passengers, with economic consequences for the owner.

The study comprised

1. A design appraisal to get to know the vessel and prepare an onboard survey and test schedule.
   
2. Onboard testing by the crew observed by DNV.
   
3. Finalising report with list of findings.
   

Following weaknesses were revealed with room for improvements:

1. A single fault in generator lubrication system which would shut down enough prime movers to leave the vessel with inadequate propulsion power for schedule keeping. DNV and SOLAS safety was not compromised as the vessel had adequate propulsion to move and steer, but the vessel could not maintain necessary speed to reach the next port of call as scheduled.
   
2. A single fault in the black water system leaving the vessel without black water service.

The studies did not include the likelihood or frequency of an incident happening, only the consequences if it should happen.