We chartered a boat from St Thomas last year that did not have onboard WiFi. To handle both USVI and BVI we rented a wireless hotspot from

https://www.cellomobile.com

The hotspot worked well (except for in Maho/Francis Bay on the USVI, but I think the cell phone reception is poor there), and handled WiFi for the six of us (perhaps not very intensive). It is cheaper than Renport.

No affiliation to Cello.