waikiore 400 Posted October 4, 2016 Share Posted October 4, 2016 Yes the Cavallis we go through too however I am fully concentrating at the time particularly with a sea running and I have experienced a fair bit of tide set there too, bit like the Rimiriki -Wide Berth area, have taken big boats through the inside with not much speed hi sun and spotters. Quote Link to post Share on other sites
John B 106 Posted October 4, 2016 Share Posted October 4, 2016 Love the Rimariki's, somewhere I have a similar chartplotter photo of us 'anchored on the beach' there too. I just remembered about this one... Thats our track right through an island , must be a fault with that chart eh. 1 Quote Link to post Share on other sites
rigger 47 Posted October 4, 2016 Share Posted October 4, 2016 On the 5nm off the coast - there is a voluntary code for vessels with oil or other harmful liquid cargo - 5nm - till alteration to make port is required. If you have a plotter showing you out of position check what datum it is on and what datum the electronic charts are in. Also check if some fiddler has put in a manual offset. Also check how many sats the thing is picking up - in some places in the sounds I have found the sat numbers below 4. another point WAAS - designed for North America - apparently it can lead to position error in other places. IMPORTANT!!! check your smoothing function - recently I found a GPS that had no error when stationary but 200m at 10-12knots - the position was being smoothed / averaged thus was not real time. Most GPS unit will smooth the speed but it appears now that some do it to the position with out taking the vessel speed into account!!! On electronic charts - they need to be updated - unfortunately there can be years between updates by some suppliers - not to mention several hundred dollars for every update in some cases. Quote Link to post Share on other sites
eruptn 95 Posted October 6, 2016 Share Posted October 6, 2016 Another minor player here is global plate tectonics, the bays and islands are moving too ! Since 2000 Auckland has moved eastward about 70 mm and north over 600 mm. That waypoint you made in the marina berth in 2000 is now over 600 mm out, and in 7 years time will be over a metre out. Follow this link for a plot of the northerly component for the AUCK(land) and TRNG (Tauranga) cGPS sites: http://fits.geonet.org.nz/plot?sites=LI.AUCK,LI.TRNG&typeID=n&days=7000&type=scatter and follow this link for a plot of the easterly component for the AUCK(land) and TRGN (Tauranga) cGPS sites: http://fits.geonet.org.nz/plot?sites=LI.AUCK,LI.TRNG&typeID=e&days=7000&type=scatter Just be thankful your not over in Gisborne: easterly movement http://fits.geonet.org.nz/plot?networkID=LI&siteID=GISB&typeID=e and northerly http://fits.geonet.org.nz/plot?networkID=LI&siteID=GISB&typeID=n Quote Link to post Share on other sites
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