Cruise ships are getting huge. The crowd you see above are all getting into one lifeboat. Its a test of a new double decker lifeboat with a capacity of 440 passengers. When the MS Princendam sank in 1980, there were only 350 passengers and 200 crew. That was a huge rescue effort. Next one might be ten times as large.
MarineLink has the story on the lifeboat.
Chuck Hill's CG Blog 
How many mass rescue rafts fit in a Dolphin? Even the Jayhawks seem undersized when one looks at the Cormorants that our neighbors to the North are flying or the S-92 that replaced the Seaking in the UK.
Lots of parts to a solution, but how do you rescue 5,000 people? We are expecting to be able to temporarily shelter 500 illegal imigrants on the OPCs. Obviously we would need merchant vessels to assist, but unless it is another passenger vessel they would be unable to feed and shelter such a crowd.
Just providing enough water would be an issue.
gCaptain has an interesting editorial about the personnel casualties that have resulted from manditory lifeboat drills. “WHY ARE LIFEBOATS KILLING SEAFARERS” http://gcaptain.com/why-are-lifeboats-killing-seafarers/
Video of the boarding can be seen here: https://www.youtube.com/watch?v=CPQ0YfApDs4&feature=share