There are no commercial motorized rentals or services allowed on Magens Bay Beach - however local residents can bring their boats into the bay , outside the swim buoys, and take family members or friends wakeboarding, skiing or tubing - it is not particularly common but more likely on weekends. Often the mega yachts anchor at Magens and run jetskis and ski boats.
It really is only the last few years that any sailboats came in for overnights at Magens and since the BVI closure and more so during the height of the winter sailing season, Magens was very popular with vessels waiting out the lockdowns or waiting to go North or South for Hurricane season.
Glad to hear your crew enjoyed the USVI waters, I have been living and sailing here for over 40 years and rarely bother with the BVI at all anymore.