The map of Indonesia. There are thousands of smaller islands not showing on the map.
Apart from the many ships that China is going to make for Indonesia, Indonesia can consider connecting islands with larger inhabitants through quake-resistant bridges
We have been trying to build super bridges to connect those major Islands, from 3 proposed bridges, only one that had been granted a green light and built, it is a bridge to connect Madura Island and Java Island where the bridge of Sunda strait is still being evaluated and the Bridge of Malacca is rejected.
The cause of the problem is mainly due to Indonesia's location on geographical map. Two of five Indonesia's major Islands, Sumatera and Java are located right on the pacific ring of fire where the historical Mt. Krakatoa is also located there.
Sunda strait bridge is nearly impossible to be built because the risk of collapse during a big earthquake hit is high, technically, Indonesia and Japan suffer almost the same fate about standing right above the moving grounds. There's no quake resistant big infrastructure that may hold the devastating damage of the typical ring of fire's earthquake. City of Kobe in Japan was first designed to be quake resistant and see what happened to Kobe after an earthquake hit Kobe in 1995.
Islands which are located in Eastern part of Indonesia mainly separated by deep and wider seas (Compared to western part of Indonesia which are separated by straits and relatively shallow waters) that results on impossibility of building such bridges.
To make it simple:
Islands in Western Part of Indonesia: Shallow and narrow waters but full of possibility of being hit by big earthquake due to its position towards pacific ring of fire.
Islands in Eastern Part of Indonesia: Less volcanoes and mainly not located right on the spots where the ring of fire is located but the waters are Deep and Wide.
You see, our country's archipelago makes the establishment of key massive logistic infrastructures such as super long bridges nearly impossible to be built. Therefore, the most possible way is to acquire huge number of ships to transport logistic from one Island to another.