Adventure in a City with Canals, remote dream by Gnat

In a giant cavern, fed by rivers, or maybe an underground city with canals. The action is primarily in one small section of a turning basin in a canal (widened to allow ships to pass/turn etc). There are docks sticking out into the water, lots of cranes for raising things, and people around but not crazy busy. And there is no sky above, just darkness, but not night.

There is a navy ship of some type with little other navy ships, the captain is addressing a gathering of people/navy crew in smaller boats and two navy sailors pretend to be dolphins and leap up out of the water to salute him.

To get away I, floating in the water, grab the end of a very fast kayak like boat with a motor, a bit worried about the engine and once he gets going my finger gets caught in an opening and I can't let go, we roar past my destination and finally I worm free and let go, but don't stop very well and have to swim against my momentum.

At some point I am on sort of a street corner, as if in NYC where they do construction and have a canopy of scaffolding, but this is over water, and the "sidewalk" is some type of floating carpet on the water.

I have to cross one section that is missing carpet so I clamber up onto the scaffolding (nervous for some reason? something in the water, animals?). While up on the platform I realize there is an image on the carpet.

Sort of a cartoon of a pumpkin creature/sprite, a flame/ice creature/ sprite and some other cutesy character/thing, and they're all in a box.

Someone says "Hey, look at those other symbols", it is some friend of mine and we have been trying to figure something out about the city, and the symbols next to the characters at the bottom right are three ladders with bulges in them at various points and....I can't see them now but there were more.

Then suddenly in the vacant lot to our right (really more of an alley of trash, not water this time), suddenly the three creatures appear in a box, alive now, but sort of sitting in a broken tv case or something.