I just now checked Lowrance website. The LMS 320 manual is available as a download. Here is the site.
http://www.lowrance.com/upload/Lowra...971_092502.pdf

If for some reason the above link does not work, go to www.lowrance.com click on downloads, click on manuals, then click on LMS 320. It will be in PFD format and you can print it from there.

I printed a copy for an older LMS 160 I used to have from this site. When I printed it I used a very high quality photo type paper that was water resistant ant the manual held up very well in the boat.