Hey Five Faces, on the return from Tortola do not cut it that close, its always easier to take an earlier ferry and have the ferry terminal hold your bags and walk around CA and eat and shop to kill time.
Much less stressful than missing flight due to long airport lines (trust me that sucks)
If you call Kevin he will meet you at the baggage carousel and get you to the next ferry, he has called ahead for us before and made sure they would still be there when we were close on arrival due to snow storm delay in the DC area. We have used just about every ferry and they all get you there within 5-10 minutes of the times scheduled.