I heard that Noland Engineering is developing an engine monitoring
system that can interface with sensors / gauges using an NMEA 0183
format, rather than the NMEA 2000 format. I'm not an expert in this
area, so perhaps you should check it out for yourself. I think they
call it a vessel monitoring system. I'm familiar with their
multiplexer and expander products, and they work great and are
reasonably priced.

www.nolandengineering.com