Fig.: Ctrec C-Net 2000
C-Net 2000 was developed by Cetrek for marine devices. It uses the CAN bus at the lowest physical level, but does not use any higher level implementation of CAN. C-Net 2000 is therefore a proprietary protocol that only works with Cetrek devices. Many Cetrek display devices include a gateway for NMEA0183 and C-Net 2000 so that data can be exchanged between the networks. C-Net 2000 does not use any special connector technology and relies on screw terminals, which makes installation much easier and cheaper. Cetrek has now ceased its production and sale of marine products. Some installations can still be found on old boats. Cetrek devices had a good reputation for durability and reliability. The display devices also had a well thought-out operating concept and were easy to read.
open-source
There is no separate open source implementation for the C-Net 2000, as the Cetrek device series were not very widespread.