Yup. When I lived in Ft. Lauderdale, I had discussions with a couple of crew agencies for part time work on my time off as CE on an ATB. Couldn’t get a workable schedule, and, to be honest, not sure that I had the attitude for the job. . . . but yeah, lots of crewing agencies in the area.
You beat me to it, just what I was going to suggest.
@Jeffro MPT in Ft. Lauderdale is by far your best bet for getting this sorted out. If you can then go and see them in person and talk to the ladies in the front office. Be real clear about what you have now and where you’re trying to get to in the future. They will set you straight, no problem.
MPT will provide answers but the reason I linked the Bluewater info is they have facilities in Antibes as well as Fort Lauderdale and might be a better long term relationship for a yachtie. If the OP lives in Lauderdale then further USCG training can be done at MPT.