I replaced the Navnet 3D BB system with the latest Furuno gizmos.
The good news is you don’t need a TZT3 plotter for in the cockpit. The TZ2BB can control 2 displays independently. So I replaced the MFD in the cockpit with a touchscreen monitor and a Furuno control pad in case you don't want to use the touchscreen. This saves power. This was for me the main reason to replace the Navnet3D. The latter is very power hungry.
What I also did is replace the two NAvPilot computers with the 700 series. For this you need to by the computer and the operating console only, the rest can be re-used. The 700-series is compatible with the TZ2 using NEMA-2000.
I also decided to replace the 4 B&G instruments with Furuno FI70s giving you much more options on displayed data (like tue wind information). I kept the B&G CPU and graphic displays. They still provide the speed/depth/wind data.
In short what you need is:
- TZ2 Black Box
- Radar power supply
- Shipmodul programmable NMEA converter
- Conversion set for the inside Furuno control console
- Conversion set for inside display to make it touchscreen
- Active HDMI extension cables and active USB extension cables
- NMEA 2000 cables and joints
There is more but let me know if you need the details as it is quite an extensive conversion.
In the end you may want to consider to move to another brand altogether. But because of the Radardome and the AIS transceiver that may give you a comparable price tag in the end. I know of one A54 that did a full B&G conversion and he spend about 20k$ on it. My conversion was much less but I saved a lot on using a few secondhand parts. Occasionally Ebay can offer nice deals on parts that were taken off boats from people that have more money then brains and always want the very latest.