PORTLAND — The Maine Department of Transportation and the city of Portland are breaking ground today on a new pier big enough to host the world’s largest cruise ships.

Construction for the $4.8 million deep-water pier will complete the vision for the Ocean Gateway Marine Terminal, doubling berthing capacity for cruise ships and other large commercial vessels. The project is funded by a transportation bond approved by voters in June.

Today’s 11 a.m. ceremony coincides with the final cruise ship visit – by the Crystal Symphony – of the city’s record-setting 2010 cruise ship season.