According to the studies, building a scaled-down version of the Daniel Island proposal would be the quickest way for the port to expand. The authority has not endorsed any of the three potential expansion sites and will continue to analyze the three options.

At its latest monthly meeting, the authority's board agreed that each of the three sites has positives and negatives. According to the study, construction of a port terminal would take about seven years on Daniel Island or in Jasper County and about 10 years at the former naval base, which could be heavily contaminated.

The authority has estimated the port will run out of capacity within the next six to eight years. Shipping volume has risen about 16% during the past year. State and local officials believe a port expansion is necessary for South Carolina to continue attracting foreign investment and tapping export markets. The Port of Charleston is the country's fourth-busiest container port.