Re: NMEA over Bluetooth
The GX2150 fixed the primary issue of requiring 3 unidirectional ports (1.5 bidirectional) because it needed a mix of 4800 and 38400 when talking to some devices. The GX2150 is also a lot of money though.
The Lowrance Link 8 appears to have the same basic feature set, doesn't have the NMEA headaches of the GX2100, and is less money than the GX2150 (or even less than the GX2100 was when it was being heavily discounted).
The Simrad RS35 is about the same price as the GX2150, but has the option of a nice wireless remote mic.
Both also talk NMEA 2000 (CAN Bus), not only 0183 (RS422/RS485/hacked RS232).
1986 Pearson 28-2 "Elena"