Is there is a ferry from Norway to Latvia?
There is no direct ferry to the Nudist beaches of Latvia, if you've meant that.
I'm also afraid there couldn't be a direct fairy from Norway to Latvia. If you look at the map, you would see such ferry would need to make a big crook between Denmark and Sweden. Possibly, there could exist a ferry from Norway to Germany; from Germany, you could travel to Latvia by ferry as well (Ventspils city).
It could be quite an expensive travel, overall. Don't get backed to this idea and take a regular flight
could be 10x times cheaper and quicker.