The river Navisence formed the magnificent Val d’Anniviers in Wallis, southern Switserland. One of my favorite places in the world and visible on Google maps.
Navisence was the name I gave to my first PC when connecting it to the LAN we were deploying at the university dorm around 1996. The computer was a 200 MHz Pentium MMX which was running Windows 95 at the time. Later on it turned into a dual-boot with Suse and eventually around 2001 became a very useful file-serving NAT router humming away on RedHat when that still was a free thing. Eventually by 2004, the hardware started breaking down and was taken out of use.
As far as I remember, I started using Navisence as my nickname on Yahoo! Pager when it was launched in 1998. Possibly, I used the name before as a nick on some LAN games at the dorm. From then on, I used it more and more for IM, email addresses and eventually this domain, which I own since December 2005.