Static IP's / Multiple Routers

Hi All,
Here's my situation, I run a simple wireless network for our boat club at the marina I dock at...We piggy back off of the marina's office Internet connection and up until recently it has been a simple matter of running the Marina's Internet connection from the modem into our(Boatclub) Wireless router and then plugging the Marina's Office computers into the wired ports in the back of our router. But now the situation has changed.
The marina is putting in a video security system that they can access from the internet, and they were told they needed a Static IP to use this feature, so they changed their ATT internet plan to the 5 static IP plan and ATT installed a Netopia router. So the hardware now looks like this:
Dsl line, into the Netopia router, Hardwire from port 1 into the marina office, into another router for their computers and the camera system....Then from port 2 of the Netopia to the Boatclubs Linksys WRT54G running DD-WRT firmware.

So I have the internet back up and running to the boatclubs wireless, but what I want to know is how to set up our router with one of the 5 static IP's, and how to use the feature in the router to be able to access the router from the internet at my home.
I have the paperwork from ATT that tells me all the IP's and info...I just dont where all the info needs to be put into our router, and if any changes need to be made to the Netopia Router....I'm just simply lost when it comes to setting up multiple routers.
When I go to IP Chicken from our wireless network it gives me the the Marinas "Gateway IP" instead of the Static IP I am trying to set up.
Any help with this would be apreciated.
Thanks in advance,
Mike