From the port side of a replica paddleboat chartered by the Virginia Port Authority, two strips of earth extending perpendicularly from Craney Island look smaller than they are.

The dikes, each 2,000 feet long and 500 feet across, are being formed with tens of thousands of cubic yards of material scraped from the bottom of Hampton Roads waterways.

Aboard a cruise Thursday to commemorate the eastward expansion of the future Craney Island Marine Terminal, Heather Wood, the authority’s director of environmental affairs, explained that a third perpendicular dike will extend from the tip of Craney Island.

The ends of the three dikes will be joined with two more dikes parallel to the island, and the space between them filled with more material to create the future terminal pad.

“This” — meaning between the existing two dikes —  “will be the first 200 acres of the Craney Island Marine Terminal that we expect to open in 2028,” Wood said.

The first two dikes first became visible during low tide in about January. The VPA considers them an important milestone in the $1.2-billion project’s first phase.

When it opens, the terminal will feature a 3,000-foot pier, six cranes and a dockside depth of 52 feet.

The project is making headway after about $27.4 million in state funds were appropriated in fiscal 2012.

Rodney Oliver, authority interim executive director, explained that the U.S. Army Corps of Engineers first started using Craney Island as a dredge deposit site 60 years ago.

The island then was six miles wide and two miles long, and its capabilities as a deposit site have kept growing, Oliver said.

It has “continued to hold more dredge disposal material than we ever thought was possible,” he said.

Turning it into a marine terminal was conceived 30 years ago, Oliver said. Wood said several politicians have pushed it along, including former governors Mills Godwin and George Allen and U.S. Sen. Mark Warner.

Construction of the dikes and several underwater footings began in 2010, Wood added.

A minute portion of the masses of dredge material that has formed the two dikes came from a project earlier this year to clean out Bennett’s Creek, said Mike Darrow, water resources division chief for the corps’ Norfolk Division. “The cutoff is the James River Bridge,” he said.

The Craney Island project presents significant opportunities to grow Port of Virginia-dependent distribution and warehousing businesses, some of which have already located in Suffolk.

As cargo volume continues to increase, after falling back during the recession years, the port is moving to capitalize on an expansion of the Panama Canal that is expected to dramatically increase the number of larger container ships sailing for the East Coast.

“The trend is bigger and bigger and bigger, all the time — the mega ships,” said Alison Winn, process improvement manager with Suffolk-based California Cartage Company, a deconsolidation warehouse whose primary customer is Target.

Winn was among dozens of folks along for the ride Thursday.

“This just places us in a much better position to handle massive volumes,” she said. “To see the port authority take such steps to ensure growth is encouraging.”