Several year's ago, I did exactly what you are thinking about with BVIYC. At that time, the captain was able to catch a ride back from Norman on one of the boats that took employees to work - probably what is now Pirates. He made his own arrangements for this.
If this isn't possible, you can probably drop the captain off somewhere else on Tortola like Trellis or Sopers. You may have to pay his or her taxi fare back to RT.
Fred