Summary
During rather poor transmission (tau_cso=0.19), transit tracking was done on 3c273 and CenA (elevation at transit = 76 and 27 degrees, respectively) :

The seeing was about 0.9" during the former and 0.5" during the latter. No obvous step is seen at transit in the former, and a 6" sharp step is seen in the latter, implying a step size at the horizon of 6.7". This is to be compared with ~7.5" seen on 01 May 2001.