There are reasons why a good mariner uses multiple systems to verify his/her location. This photo of the GPS located at the helm was taken as I was leaving Bahia Concepcion. The little triangle is Si Bon and the yellow area is a land mass known as Punta Aguja. As you can see Si Bon is clearly on land...or at least according to the GPS she is. I was warned about the inaccurate Mexican charts before I left to go cruising, a GPS uses a chart card that duplicates the information from paper charts. Now I'm pretty sure that there is someone thinking right about now "gee Steve, you need to get some better equipment on that boat". Granted that both of my onboard GPS's are 10+ years old, but I also have a brand new handheld GPS and all three GPS's showed the same information and since I have seen similar pictures from other cruisers I have no intention at this time of spending thousands of dollars on new GPS's just so I can have a larger, more colorful picture of Si Bon crossing a point of land. Sooo what do you do? Well the GPS is a still a wonderful tool and one that I still use extensively, but I also do pencil and paper navigation, I use my radar, my depth sounder and of course my eyes (and a good set of binoculars). When you combine all of the sources available there is little chance that you would actually be on the yellow land mass as the pic shows. Well since all three GPS's currently show me in the parking lot here at Marina San Carlos I think I'm going to hop off Si Bon and go ask for a refund on my slip fees, adios.