Speed of the EAC

[thermalben]

A snorkler that was reported missing from near Cook Island last Monday washed up near Tallows Beach at Byron Bay last Friday (see news articles here, here and here).

Aside from the tragic circumstances in which he died, I'm impressed with how far the body drifted down the coastline. I've done some crude estimates on how far this is, and it's somewhere around 85km (the distance from the Cape Byron lighthouse to the airport at Coolanagatta is ~90kms; take off ~2kms from Cooly to Cook Island, and you're somewhere in the 85km range, give or take 5kms for headlands etc).

Over the space of four days of travel time, this clocks in at over 20km/day. This is just under 1km/hr or half a knot, but compared to the regular speed of the EAC, it's actually quite slow (normal speeds are around 5kts, especially in February and in the absence of a strong southerly wind). The EAC flows quite close to the coastline at Cape Byron - sometimes as close as a kilometer or so, but it can spin off small eddies close to the coastline which would slow the speed of any surface flotsam.

Current SST data shows a finger of 27° water extending through this region (here), but I'm not aware of any current-recording devices in the area (MHL's Byron buoy has been offline for ages, and I'm pretty sure it's not fitted with a current meter anyway). Still, it illustrates how complex the ocean is - imagine launching a search for a boat or plane (as actually hapened off Byron a month ago as well) - with EAC speeds up around 10mn/hr in parts, the search area widens considerably with every passing hour.

[hammer time]

yep. amazing.

[Dave]

He shoulda hooked up with the turtles...

[thermalben]

Uther - to be honest, I don't know. I've never surfed nor seen them, and I can't really put a size on those kind of locations that break so rarely. However, although it's not going to be an enormous swell event (it'll be very large, but we're likely to have seen similar sized events during the last 12 months), the swell direction will be good from the east. I'd certainly give it a look - with fresh to strong onshore winds on Thursday you'll hardly be missing anything epic oceanside at most locations.

[barstardos]

Thanks for that post Ben, as a regular spearfisherman its reassuring to know he didnt get eaten by a shark. Still, he must have drowned and thats bad enough.

Regarding the EAC, I know sometimes it creates great steps in the ocean. We were sailing up the east coast a few years ago and about 20 miles offshore of the Tweed Coast we had to sail through half to one metre high steps in the ocean surface. But they werent standing waves or or normal ocean swells.
does anything know anything about these things?