You can get to Demak Laut from Petra Jaya or from Pending (Barrage bridge). Demak Laut is an industrial area. Lots of warehouses, sawmills, manufacturers like Nestle, Maggi, etc can be found here.
But just before you turn in to the industrial zone, you’ll see all these new houses and apartments on the right. From Semariang to Demak Laut, new housing estates keep sprouting up… and I thought we are in recession 😐