Accuracy of NSW MSB maps versus new GPS

[Crocodile]

Hello All,

I have just installed a new Dragonfly GPS/Chirp Sonar combo.
I took a fix next to the north east corner of the Fingal boat harbour pontoon yesterday.
Chart is Tweed-front.pdf, fine print states Datum WGS.84 (up to 100m of error).
Chart says 28 12.080S 153 33.837E.
My GPS 28 12.000S 153.33.843E.
Which is 148m of error NS and 11m EW.
GPS is WGS 1984, which I am assuming to be the same as the chart datum.
Has anyone else made a similar check with chart/GPS?

[Noelm]

So, you are saying your GPS is correct? Might be that the chart is right? That said, I have taken a very exact waypoint (tied to the jetty) and sometimes it is way off, even with modern GPS that is "supposed" to be much better than the old ones.

[McKnight]

I agree with the GPS co-ordinates, well google maps backs up the GPS and says the chart co-ordinates are roughly 150m point to point out.

[Crocodile]

Hello Noelm,

not a question of who is right/wrong, but rather has anybody else seen discrepancies like this.
100m is a lot of square searching to find a small reef.

[SatNav]

....not a question of who is right/wrong, but rather has anybody else seen discrepancies like this.
100m is a lot of square searching to find a small reef.

Definitely, typically to do with anomalies in the charts but could also be related to issues caused by mounting location/s of units with internal GPS.