Lego Batman Strategy Guide 44: Rockin' the Docks, Part 1
This first area involves getting used to Penguin and his explosive pets. Use one of them on a manhole cover, and you can get a lot of studs including the purple one.
There is a red thing that, if smashed, will make a carrot. This is one out of three carrots that you have to find to make a canister.
An explosive penguin can be used on the chain-link gate, which will lead to a new area.
Go on and take out the cops here, and then go to the corner of the shed and bust up some stuff. Reform the pieces into a fan, and use it to get to the top and bust another red tank thing for the second carrot.
Smash everything else, and use an explosive penguin on the silver door. You can pull the Semi truck out and fix it with the parts that should be laying nearby, but it will take about four repairs. Use Bane to move the other truck that is blocking your way while you are at it.
You can drive one of the trucks into the gate, but you might want to take out the bad guys before and after you crash through it. By the way, you may notice a place with a glass frontage unfortunately, you will have to wait until Free Play level to get any of the rewards here.
From here, you can get in the truck and drive to the one big storage unit and jump up to the top of it. This is about the only way any one of these characters on this level can get to the top of it. Go ahead and smash the red tanker up here for the third carrot, which will automatically give you the First Canister.
Now, I believe that there is a huge pressure platform that will require at least one Semi truck in order to open the doorway there. However, you should be able go back and get the other driveable semi truck and park it on the other pressure pad. The cargo hold will open to reveal the Second Canister.
Don’t go through the door to the next area just yet. Keep working to the right, and going until you reach the end of the dock. You can blow up the silver caps on the wooden dock struts if you want. There is a boat that you can jump to, and Bane can grab the orange handle and get some extra points by removing a section of it and throwing it away. He will find the Third Canister. If he keeps going, he will have a purple stud on the next dock.