Hi precythrower,
Ship Simulator Professional is not really intended for home-computer use, but is - as the title suggest - made for professional use.
It is not really meant to be a 'game' like SS08+NH is, it's meant for training purposes, or demonstrations, in the maritime sector. Schools can use it to educate the students, companies can use it to demonstrate what they do, to potential customers, things like that. It has the same contents, ship and environment wise, that SS08+NH has.
It's made to be used in combination with a variety of navigational software and/or equipment aswell, so unless you have thousands of Dollars/Pounds/Euro's worth of equipment, it's not really of that much use (at that cost).
As it's a very expensive piece of software compared to the game version too.
But you can find the rest of the info right here on the main website; http://www.shipsim.com/products/ship+simulator+2008+professional.php
If you have the money and the desire, plus a decent enough pc, you can of course always use it at home, but that's upto you of course.
Hope that answers your questions,
Regards,
Fred