Ship data and a satellite image in June 1987 showed the Leeuwin Curren
t as a warm, low-salinity tropical stream travelling southward inshore
of the 180-m isobath with near-surface speeds up to 0.9 m s(-1). Fart
her offshore, where the waters became progressively more subtropical,
the southward currents were also quite strong-0.75 m s(-1) above the c
ontinental slope and over 0.4 m s(-1) out to 70 km beyond the shelf ed
ge. Beyond this, a doming of 150 m in the temperature structure at sev
eral hundred metres depth drove a cyclonic eddy that had its maximum s
peed of similar to 0.5 m s(-1) in a ring at 200-400 m depth. The prese
nce of the eddy was confirmed by the path of a drifter. Geostrophic cu
rrents and currents measured directly with an Acoustic Doppler Current
Profiler showed good agreement. The warm 'shoulder' of the Leeuwin Cu
rrent between the 105-m and 135-m isobaths was a biological oasis char
acterized by, inter alia, several fish schools at least 10 km long and
1 km wide and with vertical extents from 20 m to more than 100 m dept
h.