A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Ronald van Riet
Date: 2017 Aug 25, 01:14 -0700
In addition to their Aviat series, Aristo produced the Naviat which was optimized for nautical use. I don't know exactly what functions it supports, but from the picture on http://sliderules.lovett.com/aristonaviat661/aristonaviat661.htm it looks like it has some useful functions for mariners.
Good luck with it