GPS
I just got a Standard Horizon CP150 Chartplotter with WAAS (synchronous-satellite reference) which is supposed to provide 6 foot accuracy! All GPS will have this capability in future so try this. I have not had the opportunity to use mine yet because without the map chip the minimum map span is 26 miles! From what I have determined so far though, this is a much better deal than anything on the market at under $400. I got mine at West Marine on sale with the $150 chip included.
