One Panasonic Toughbook CF-H1 Field tablet PC. This currently runs Linux but can run Windows (license sticker for Windows 7 Pro included). This is a tough, ruggedized device with IP65 rating, able to withstand a 6 foot drop and has a sunlight viewable screen. For full specs and review, see here.
I've used this as a cockpit chartplotter, which it does well, except the touchscreen is the resistive type, which isn’t the best and scrolling a chart like that is frustrating. However, as the charts scroll happily it hasn’t been a big problem. Importantly, they knew this when they made them and therefore also included is a Wacom digitizer with pen, which is brilliant, precise and even has right-click and digital eraser.
The best bit is that you can take it with you……..I have used it with a universal mount on the console and simply detached it to take it home/off the boat at the end of the day.
It does have a built-in GSM card, which supposedly can do GPS as well, although I've not tried it as I have all my boat NMEA on Wifi, so it got GPS location, AIS, wind speed, depth, etc. from that instead. It's currently installed with Navigatrix, a Linux distribution with OpenCPN 4 and a lot of other useful marine bits pre-installed. I may have left some charts on there for testing, which you should obviously delete once you're satisfied it's all working.
It's in superb condition, and I've replaced the original spinning drive with a much faster 64 GB SSD. Comes with a power supply and a magnetically attaching port replicator, which provides 2x USB ports and Ethernet. Built-in are Wifi, Bluetooth, a rear camera, a barcode reader (probably not much use) and a GSM/GPS card as well as a bunch of configurable buttons on the side of the screen. Digitizer pen included and two internal batteries – I ran it off 12v, but the batteries which swap over automatically when the first is discharged saw me through my outings).
Asking for £150 + add costs for insured postage.
I can send additional photos/details if requested.