The most common Expedition configuration on a race boat is a dedicated computer in the nav station and a roaming tablet.
While it is possible to run Expedition on a tablet, there are several advantages to having a fixed computer in the navstation, with everything displayed on the main computer being reflected on the on-deck display, including:
A physical connection to the instruments, so lessens the risk of lost connections
There is no chance of dropping it over-board or otherwise damaging it
A permanent power supply
Note that a good, fast wireless connection is essential.
Historically, the main tablet used has been the Panasonic CF07, however these are no longer produced and are becoming obsolete. In addition, they can only be used with Windows XP, which is also obsolete.
Apart from water-proofness, the other main issue with many tablets is daylight viewability.
Various options (July 2014)
Sony Xperia: 10.1", IP55, 426g. Android. Not as rugged or waterproof. Under 500 nits, so daylight viewability can be an issue.
Microsoft Surface - not ruggedised.
Apple iPad - common, but not ruggedised, so a waterproof case may be required. Daylight viewability can be an issue.
There are several solutions to use a remote tablet with the navigation computer.
Remote desktop is generally faster than VNC. This is because the remote desktop system sends instructions on how to draw the screen, whereas VNC systems generally send a picture of the desktop from the server.
Microsoft Remote Desktop
Remote desktop tends to be faster and more secure than VNC.
VNC tends to be slower and less secure than remote desktop, but can be used by more users.
There are several options.
Android, Apple and Windows Client Software are free, but server software is not.
Splashtop. Easy interface, but less popular than it once was.
The IP code rates the degree of protection against dust, water etc.
The first digit indicates the level of protection that the enclosure provides against access to hazardous parts (e.g., electrical conductors, moving parts) and the ingress of solid foreign objects.
5 - Dust protected,
mostly dust protected
6 - Dust tight, no ingress of dust
The second digit indicates the level of protection that the enclosure provides against harmful ingress of water.
4 - Splashing of water
5 - Water jets
6 - Powerful water jets
7 - Immersion up to 1m for 30 minutes
8 - Immersion below 1m for indefinite period