So I'm reconfiguring the gauges in my zb21, making a new laser etched billet plate. I plan to do a 4.5" tach with 4 other smaller gauges. My question is this. Gps speedo is a no brainier but about $400 for gauge and receiver. What gps speedo do I carry with me everywhere? My iPhone, and it's a free app. And it will always be with me in the boat playing the tunes. So then I ask: speedo gauge or iPhone?
Matt