The only reason you need to go there is to get the "special number" that Captain Ziggs uses as his combination in his quarters. It is on the desk :the number 516 is translated into "0516" to open the secret closet.
its in the museum on mainstreet of steamworks island :)
It's Steamworks Island #14th Island
(The solution is at the related question "How do you beat Steamworks Island")
the crab on steamworks island is next to the living quarters
The mayors term of office is 50 years
You go to Steamworks and head to the museum and there is the Deogen
steamworks island
There is a video walkthrough at the related link below. There are written WikiAnswers solutions at the related questions, as there are for all Poptropica islands. (How do you beat Steamworks Island) (What is the walkthrough for Steamworks Island)
Steamworks island
you can get it on the far left of steamworks island, past the living headquarters.
how to do the bridge terminal on poptropica's steamworks island
jump