The abbreviation in the title means "Free On Board" or "Freight On Board", which pertains to the shipping of goods where the party (buyer or seller) pays for shipment and loading costs.
The name of the ship on which the real plates are smuggled is the "Brazil Maru". The real Brazil Maru was a WWII Japanese ship used to transport Allied POWs and civilian prisoners under horrendous conditions during WWII. These ships were known as "hell ships."
In the conference room discussing the fact that Nicholson is in possession of the plates, it is learned from the conversation between McGarrett and Kaye that McGarrett and Nicholson attended the Naval Academy together.