A Hydrofoil or jet Foil would be more economic.
A hydrofoil is a wing-like structure mounted on struts below the hull of a boat, which lifts the boat partially out of the water during forward motion, in order to reduce drag.
The Hydrofoil is very economic and save a lot of gas.
You can easy transport with a speed up to 50 knots (93 km/h)about 50 passengers and freight. You should be able to get a second hand hydrofoil in Italy, Macao or Hong Kong.
Passenger Boat Manufacturers
Ukrainian built Voskhods are one of the most successful passenger hydrofoil designs. Currently, they are in service in more than 20 countries. The most recent model Voskhod-2M FFF, also known as Eurofoil, was built in Feodosiya, Ukraine, for the Dutch public transport operator Connexxion.
The Boeing 929 is widely used in Asia for passenger services between the many islands of Japan, in China and on the Korean peninsula.
If I had the funds, it would be good investment for me.