Considering the Grand Hotel Royal in Sorrento?
A VT member wrote the following comment about visiting Sorrento:
Hydrofoil to Capri by Willettsworld
The hydrofoil to Capri leaves the port in Sorrento roughly every half hour, takes about 25-30 minutes and costs about 20 euros return. While you're waiting to board, you can walk around the small marina or sit in the small park area by the ticket offices.