As part of the Three Seas pro­gram at North­eastern Uni­ver­sity, stu­dent Stephanie June par­took in a diving expe­di­tion to examine coral reefs off the coast of Panama.

But her fondest memory of the under­water excur­sion had nothing to do with exploring the so-​​called “rain­forests of the sea.”

That’s because midway through her deep-​​water dive, she expe­ri­enced a once-​​in-​​a-​​lifetime encounter with a harm­less 30-​​foot-​​long spotted whale shark.

Of meeting the largest living fish species on the planet, the senior biology major says, “Out of nowhere, this shark was right under­neath me. Very rarely do you get to see them.”

Now in its 28th year, the Three Seas pro­gram enables stu­dents to study and con­duct research in three diverse envi­ron­ments with many of the world’s leading marine sci­en­tists.

Run by the Marine Sci­ence Center (MSC) at North­eastern Uni­ver­sity, grad­uate and under­grad­uate stu­dents spend the fall semester at the MSC in Nahant, Mass. The only major, year-​​round marine lab­o­ra­tory in the Greater Boston area is just 12 miles from campus and has class­rooms less than 100 yards from the Atlantic shore­front.

In the winter, stu­dents study at the Smith­sonian Trop­ical Research Insti­tute in Panama for three months, fol­lowed by a two-​​month stint in the spring on San Juan Island, Wash.

The pro­gram — which includes daily lec­tures, field­work and diving expe­di­tions — is taught by marine biol­o­gists from leading research insti­tu­tions, including North­eastern Uni­ver­sity, Brown Uni­ver­sity, Scripps Insti­tute of Oceanog­raphy, and Uni­ver­sity of Cal­i­fornia cam­puses at Berkeley, Santa Bar­bara and Santa Cruz.

Senior biology major Sonia Ahrabi-​​Nejad praises the expe­ri­en­tial learning oppor­tu­ni­ties at the core of the pro­gram. “By being out there for an entire year, in three dif­ferent labs, with top research pro­fes­sors, I feel more pre­pared for grad school and a career than if I was just sit­ting in a class­room,” she says.

“You’re not just going out and enjoying the Caribbean for two months,” June adds. “You have to work hard.”

This fall, North­eastern expanded the marine biology con­cen­tra­tion to a marine biology major in the Col­lege of Sci­ence.

Sal Gen­ovese, director of the Three Seas Pro­gram, com­pared training stu­dents in the new dis­ci­pline to preparing minor league ball players for the big leagues. “Through the new major, we can home grow our own marine biol­o­gists,” he says.