The USCG GMDSS course is 10 days, same as the MCA course. The IMO model course is twice as long, but only because it has two weeks of Spoken English Language lessons. That should not be necessary in a country where English is the native language.
I have heard it said, that the US is the only country that requires obsolete radiotelex instruction. I’ve also heard that the MCA GMDSS exam is much more difficult with multiple modules. Failing a module results in a hefty MCA retest fee for that module.
There are at least two US schools that teach both a USCG and a MCA version of the GMDSS course. One of the schools has in house GMDSS instructors. They other school uses an American contract instructor that teaches GMDSS at several different schools around the US. Neither of those schools was Willing to provide me a with the combined USCG / MCA GMDSS course that I asked for.
The long and the short of it is, that anyone who wants both a USCG and a MCA GMDSS certificate is going to have to take this lengthy waste of time and money course twice.
Also, as I understand it, the MCA requires that the course be renewed every five years. The USCG considers the course good for life. I wonder if sooner or later Port State Control in some countries may not accept USCG GMDSS certificates that are over 5 years old?