Unless the law has changed boats under 20 feet without power do not need to be registered. Perhaps they have you confused with a powerboat. Most of the people just assume powerboat rules.
The law has changed.. in aug (supposedly). the law used to read (non powered) boats 16' and up need to be titled and over 20' registered. it is now 16 and above need both. H16's are technically 16and change.
So far in my 10 years sailing cats.. and owning 3 i have met 1 person who actually has a title... and i have seen only 1 cat with FL reg numbers on it