But I don't find LBB7 exactly definitive on this score.
And deliberately so.
GDW understood that most merchant marine academies are "small a" types. They're academies, but they're not THE ACADEMY like Annapolis, Kings Point, or New London.
GDW also understood that attending an academy is not the only way to become an officer in the merchant service.
Contrasting the USMMA and MMA is a good way to explain this.
The USMMA at Kings Point is a
federal service academy. You don't pay to attend. You need a congressional appointment to attend. Upon graduation, you're either commissioned in the naval reserve or in any of the other uniformed federal military and paramilitary services. Fields of study and degree programs are limited. You're also obligated to work in specific industries for a certain period of time.
The MMA is a
public school. You pay to attend. You only need to meet admission requirements to attend. Much like Texas A&M with it's Brigade, you can join MMA's Regiment and use NROTC program to pay your tuition. Not every MMA student does that or needs to do that. Fields of study and degree programs are also limited, but you are not obligated to work in specific industries after graduation.
Both schools also offer what's best described as "continuing education". People already serving in the merchant marine or wanting to serve in the merchant marine can take specific courses and licensing programs for specific accreditation.
The maternal side of my family has been Down East, Blue Nose, Maritimes, and similar types for centuries. I can't begin to count the number who've worked at sea and at least a dozen have attended MMA in one form or another since the 1940s. One of my uncles even served as MMA's harbor master after his 30+ year USN career.
One cousin ran away to sea right out of high school, worked as a deckhand, served in the Mekong riverine forces in Vietnam, returned to the merchant marine, went to URI for his degree, attended MMA for his master's license, and finally retired after decades of working as a swordfishing boat relief captain in the Pacific. His younger brother went to MMA straight out of high school, put in his required active duty time, and then worked for a number of large shipping lines eventually reaching captain before retiring.
Two men, both merchant marines, both captains, both with different education and career paths.
GDW understood this. That's why
LBB:7 allows for different career paths.
You can attend the Tukera or Al Morai or whatever mega/big corp academy at 18. You can apply after graduating college or university. You can be a direct hire by Oberlindes or McClellan's or whomever after your naval or scout service. You can even sign aboard a free trader as a mop jockey and (hopefully) work your way up to better things.