hi there,
If you're cruising to Indonesia the type of cruise I believe you are after it's a South Pacific cruise.
The port of call for a South Pacific cruise can be Australia but it you can find out with the cruise ship company what their pot of call might be.
Then, you choose the type of cruise ship (size, luxury ship, etc). And lastly, you choose when you are departing.
If you're looking for discounted ship cruises then it is a good idea to book your
South Pacific cruise at the last moment.
However, if you have
special needs such as a special itinerary, a disability, etc; it is best to book well in advance so they can accommodate this.