Se res sic habet:
"mari" is also the ancient locative case (like humi, domi etc.).
Here "rego" is used as an intransitive verb.
So the correct translation is:
"music rules in the sea".
I didn't know the term "musicum, musici".
Anyway, this title was just a joke (like the English one).
Pax vobiscum ad aeternum...
jrg "nobilissimus et clarissimus suae domi rex"
