Friday, October 22, 2010

Cowabunga Dudes – A record ride on the East Australian Current

22nd Oct 2010


With really good weather forecast we were probably a little to keen to get going as a really good run would set us up for a pre-dawn arrival into Coffs. None the less we were out of the Seaway just after 06:00 EST and set off in good conditions with the now familiar morning ‘land breeze’ westerly pushing us nicely. With the wind expected to swing NE the prospect for a good run was always on the cards but with the NE’s only light, I elected to keep the Yanmar going at a low 1800 rpm just to make sure we achieved planned speed. This, it turned out was not at all necessary (by a long margin) as we picked up a ride on the East Aussie Current.
The current, as every one knows from Nimo, is a perpetual feature of our East coast but just where it is and how fast it flows, varies significantly, in fact ‘chaotically’. The BOM site has a sea surface temp forecast from which they extrapolate the current and as can be seen, it was straight down the coast past Ballina. In the absence of such forecasts, the rule of thumb is that it can be found on the 200m line (depth) but we were only in about 50m when we got a peak ride of 2.5 knots. With the wind (and the Yanmar) this gave us a RECORD ground speed of 8.5 kts. A speed we maintained for most of the daylight hours.

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