Hi,
I know Joel at Tech Diving Limited pretty well... they are the distributors of the Nautilus Software in the US.
i asked him about the 21m demo version.
If you go to their site and 'purchase' a free demo version, it will run the full version for 30days....
That gives you a real chance to test the software before purchasing.
I used to distribute the Abyss Dive Planning software and I am now seriously considering picking Nautilus up and doing the same. From my prelimimary tests it looks pretty damn good...
Tech Diving Limited can be found at
www.techdivinglimited.com
Hope that helps...
Andy