Private Sales: Bought a Boat, Got Title and Bill of Sale, but Previous Owner Didn't Register

My question involves a consumer law issue in the State of: Florida.
Reading previous posts has led me to this conclusion, but I would like verification from those who know.

The sellers who sold the boat to the person I bought her from live in Florida and I can probably find them.
If I do, can they transfer the ownership to me and if so, what is involved - documents, cost, etc. Seems that
this would bypass the person I bought her from. He's living somewhere in Europe and I would not be able
to find him. Thanks.

Private Sales: Bought a Boat, Got Title and Bill of Sale, but Previous Owner Didn't Register