How long would it take to get a legal declaration of death if there was no body?

No, I'm not trying to kill someone! I am researching a book project. If a US citizen disappered while scuba diving in Australia, would it take 7 years to get a legal declaration of death from the courts in the US, in order to probate a intestate estate in California? AND because there are no heirs to that estate, would the State of California receive the estate because that is where the real property is located?