The dredging project will bring 30,000 direct and indirect jobs to Florida over the next five to seven years, Johnson said.

A truck tunnel — slated for completion in summer 2014 — and improved rail links from the port complete the picture. With that trio of projects in place, Johnson hopes that by 2020, Miami will be able to double the number of TEUs (a cargo measure equivalent to a 20-foot container) it handles to two million.

But even with the improvements, “the port of Miami has limitations in terms of size,’’ said Donald Francey, an executive with Maersk, the biggest shipping line at the port.

While Johnson said Miami is now on its way to becoming a much more significant port, it has been a hard-fought battle.

The tunnel project had been floated for decades. Hurdles that had to be overcome before the digging began included a threat by the state to rebid the project because of concerns over the finances of the drilling consortium; where the dirt from the dig would end up; a late letter of credit; and complaints from Miami Beach about potential traffic hang-ups.

As part of a lawsuit settlement with environmental groups over the impact of dredging on Biscayne Bay, the port has agreed to pay an additional $2.3 million for environmental projects. To allay fears that blasting could rupture a fragile sewer pipeline running under the shipping channel, the Miami-Dade Commission also voted to spend an extra $23 million to make repairs before the dredging begins.

But if Miami sticks to its timetable for completing its port projects, its early advantage could be a boon.

“Shipping lines like already established routes. Being ready sets the pace,’’ said Rodolfo R. Sabonge, a marketing executive for the Panama Canal Authority. “Timeliness is quite important — you are ahead of the game.’’

Although the projects have amped up the port’s debt load, Johnson said they are essential for the port to create jobs and generate revenue. When he took the helm in 2006, Johnson said the port was losing $1 million a month.

Not only is the densely populated South Florida market attractive to shippers, but Johnson said port enhancements and the improved Florida East Coast Railway links will help the port reach other markets in the Southeast within 10 hours to three days.

Just as the Panama Canal needed to make a huge investment so it would grow, “I think the Miami port will be a very important partner. Geography has a lot to do with it but so does population and economic activity — and Florida is very important for both,’’ Sabonge said.

Port Everglades officials dismiss the importance of Miami being first out of the box. “It’s nice to be first from a headline perspective, but long-term it’s not important,’’ said Michael Vanderbeek, director of business development at the Broward County port.

Savannah is the Southeast port that Miami wants to emulate. “All the things I’m doing in Miami are things that Savannah did 15 years ago. They were bold; they had vision,’’ Johnson said.

But Miami, the closest U.S. port to the canal, will have its advantages too, he said: “We’re not 30 miles up a congested, foggy river; we’re 2.5 miles to open ocean.’’

“Miami certainly is not our major competition,’’ said Curtis Foltz, of the Georgia Ports Authority. “Our main competition is the West Coast and Charleston.’’ Both Savannah and Charleston need deep water, he said. “It’s not secret that the Southeast is the fastest growing market in the United States.’’

Eventually, the U.S. deepwater ports will complement each other, Sabonge said. “Why would they want to compete? They each have their own territory, their own hinterland to serve.’’