Just read through their site, they have solid orange reservable and white ball with orange BB sticker on their FCFS. On their map FCFS show up blue with "fc" on it. BB FCFS balls can be paid via your account once on the mooring, the cost can range $30-40 night.
Brings up another question...even though the reserved ball is shown on the BB field map, are the numbers easily seen as you approach?