Raise wages, raise benefits, make the credentialing process easier and more efficient, make it easier for retiring service members with relevant experience to get MMCs, create programs that retain sailing personnel so that people actually advance their license and stay working at sea longer, make it easier to renew, provide government funded training.
Heck if some of those things existed, I might be sailing today instead of my the career path I took after graduating from a state maritime academy almost 10 years go, which lead me to waiting in the union hall for a bit, having no luck, and eventually ending up in the pretty decent shoreside management position I find myself. Sure I make less than I would’ve as a chief mate or captain, but everything else about my position brings me much more job satisfaction.
Edit: If I could take my license out of continuity, without going through a ton of red tape and quickly, make decently more then I currently make, receive some decent benefits without the uncertainty of waiting forever for a job, I’d seriously consider it. People with credentials, waiting around on the beach exist, but the motivation to sail again has to be more attractive then whatever shoreside job they might find.