The Leonida Marine Center is a business that can be found in GTA 6.
Although the center itself has not been shown, 
According to his shirt, it's possible that Jason even works at the 'Sales and Services' department of the Leonida Marine Center from time to time.
Generally, a Marine Center refers to a facility dedicated to marine life, the ocean, or maritime activities. This could include research centers or public-facing activities such as snorkeling, aquariums, and more.
Confusingly, the t-shirt Jason owns contains an image of an eagle, smoking a cigar while dual-wielding submachine guns.
Above the eagle, the text "Let Freedom Reign!" can be seen.
Underneath the winged mascot, more text reads: "We Support All Marine Life." It's not currently clear what sort of message the shirt is attempting to present.
It is possible that the the term Marine is actually referring to a military unit that's trained to operate on land and sea, rather than its usual reference to sea animals or plants. This would explain much of the confusing imagery on Jason's t-shirt, especially given that he is confirmed to have served in the armed forces.
However, it's more likely that the Leonida Marine Center simply has some unusual imagery, given GTA's usual outlandishness, and the fact that the shirt indicates it belongs to a Sales and Services department.
We are not affiliated with Rockstar Games or Take-Two, our content is not official or endorsed by them in any way.
