I need some help identifying the type of gear I need to do what I want
to accomplish.

I am building a wired network in my boat, using off the shelf components
designed for home use, such as simple wired routers (Netgear, Belkin,
Lynksys, etc).

But I want to be able to access WiFi Internet service, such as available
through the companies that are offering WiFi at marina's, and I want to
be able to access this from any pc on my wired boat-network.

This is the opposite of what is now common in many homes. There we see
the internet (via cable tv or DSL) hardwired into a wireless router,
which then b'casts to outlying pc's. In my case I want wireless
broadcast _into_ my boat-net, and then hardwired to pc's around the
boat.

What is the name of the device I need at the furthest upstream point
(i.e. the receiving unit from the wireless ISP) that the antenna is
connected to? Whatever it is, from there I want to route to 4 locations
in my boat by cable.

I asked this on a wireless usenet group and they got completely
confused, thinking I was trying to do the common household internal
wireless from wired DSL/cable and wondering why I wasn't "getting it."
Finally one guy understood what I wanted and explained it to the others,
but then nobody had any answers. I am hoping my fellow boaters
understand what I am trying to do.

TIA

Mark