[JoMeKe]

Scot and Ron, thanks. I like the idea of the multiplexer as well. I still need to look into a new GPS antenna as the current chartplotter/antenna system is quite old. The plotter is no longer supported and I suspect the antenna is not WAAS-enabled. While I understand the GMouse unit listed on GPSNavX site works well with the software and Macs, I'd rather find one that can mount to a rail or on the mast. I'm not crazy about just having a magnetic base, though I suppose I could mount a metal backing plate at the upper helm to secure it.

Ron, Good to hear about your issues with the Garmin unit as I was considering it. I'll now continue to look further, particularly if I go with the multiplexer concept. My other thought would be to get an up-to-date handheld unit as a backup and to use as the GPS antenna for the laptop and other systems (DSC VHF, autopilot, etc.). Any recommendations on a good stand-alone antenna or handheld with a good internal antenna?