Yeah, that's still kind of a Catch 22. But my understanding is that you can get a 'portable' (Type P) FCC license...after which you can get an MMSI number.
The FCC license ain't cheap, I don't think.
Alternately...you can just push the envelope and register it to your home kayak. It doesn't really make any difference, since the number is (effectively) tied to the radio itself, and not any particular boat. You're not required to validate registration...just provide a name of the vessel. The emergency contact info that you give is the important stuff. THAT is what will be vital in rescue and recovery.
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