On our tomcat we have the raymarine main gps, as well as a standard horizon handheld, an ipad2 with navionics, and an iPhone with navionics. The one we use most is the iPad. Works like a charm and is easy to read. For a smaller boat I would vote for the iPhone if I had one. Obviously it serves multiple purposes and navionics is not to expensive as an app. My only concern would be to provide some type of waterproofing.