TZT2

[rockfshr]

Will the BBWX4 replace the BBWX3 or will both be needed to get the weather chart to overlay on plotter chart?

 

[Johnny Electron]

The future BBWX4 will be the replacement for the BBWX3.
The BBWX4 is not yet available. You will not need and can't use two receivers. Either unit will do the job.

The TZT2 also offers the NavCenter weather, at no cost, by using your built in wifi.