Bad Electronic Chart

This is from a cruising yachtsman in The Bahamas this month:

Here is another “oops” story!

We met a sailorwho has a large power catamaran. He loves to anchor at the south end of Big Farmers Cay. He told us he took a short cut to get out of the anchorage and ran aground and had to power through the sand to get out . We couldn’t believe he even tried it.  He said his plotter showed 7 feet there and he had a Garmin.  We insisted he come aboard and look at the paper Explorer charts (which he had, but left home). He was amazed that the data on the plotter was not the same as the chart. He also said he had his iPad aboard but he had updated it and lost the Explorer charts on the Garmin Blue Charts app. We included a screen shot of Navionics for that area and he ran aground north of the wreck while trying to jump the bar.  Navionics shows 7’.. . We explained to him that Explorer data was no longer on that Garmin plotter. We told him he should be using his eyeballs but he trusts his instruments. We explained why that doesn’t work in a Bahamas boating scenario!!!

So much of what is depicted here  in this Navionics chart is pure fiction & makes us wonder how this data was accumulated. It is a physical impossibility that a boat had occupied the position north of the wreck & recorded a sounding of 7.7 or 9.2’unless they were there on 10’ high tide & forgot to apply a tidal offset. The Explorer chart shows “Sand nearly dry a low Water”.

NOTE from Explorer:  If you have a Garmin chart plotter with data before February 2019, (BlueChart G2) that is Explorer data. After Feb. 2019 (G3) is Navionics, NOT Explorer data.