There are 8 fast travel points on Voyage of Despair.
In order to make these appear you will have to pick up the artifact at the far end of the ship first. The first fast travel point will show up right next to you on your left side as you pick it up. It costs 500 points to use them. You will need to open up the doors to the destination you want to travel to first, so open up every door before you do anything.
The portals are located here: (the destinations are also included)
Forecastle –> Poop Deck
Poop Deck –> Forecastle
Millionaire’s Suite –> Provisions
Turbine –> Cargo
Cargo –> Boiler Room
Boiler Room –> Grand Staircase
Boiler Room –> Boat Deck
Ship Deck –> Engine Room
As you can see there are 3 portals around the engine room/turbine/boiler room. I would suggest draining the water first so you can find those 3 more easily.
You can play this on casual and add 3 bots to make this much easier and gather enough money.