Freeboard? We don't need no stinking freeboard.

Cool pic!

It's hard to tell from your pic, but it looks very similar to the fuel lighters I've seen around Singapore Harbour. If so, no they don't typically have much freeboard - and there are a few good reasons why.

Yup, one benefit is the deck is self washing

Looks like it's full of opium.

I've seen ships similar to that which take on water to lower the middle part below the surface to get floating cargo (like oil rig components) on-board. After that, the water is pumped out and the ship rises and takes the cargo to wherever it's going.