The custom is to keep the ship in port until all the DCL booked passengers are onboard be it departure or shore excursions. It would behoove DCL to try to accomondate all the passengers trying to board in order to pay the frieght onboard buying drinks and such. Speaking to the rep. there is also the airspace issue that will arise which only allows so many planes in the air and on the tarmac. Plus there is also a number of planes that have to be repositioned. Bottom line is the almighty buck so I believe DCL will try and do what it can to get everyone onboard and pay its' fixed cost. Fox just announced 50% of E.U. flights may possibly be in the air tomorrow. 
You can't worry about things you have no control over...just pray.

You can't worry about things you have no control over...just pray.