Jan, ZS6BMN has been using the DeLorme Tracker data as well as the WSPR Beacon data to estimate the teams ETA in Perth. Jan reports that an earlier estimate of his still seems to point to April 20th. Click on the image to see an expanded view.
Thanks Jan!
vk0ek.org 
I just contacted ZL/VK0LD/MM on 4/19/16 at 12:02 UTC . . . how do I know where he was on the ship? what is the ship’s name? de KD8DEU, Al from Columbiaville, MI, USA
Hello Al,
The ship is the “RV Braveheart” and the operators from the VK0EK DXpedition is using the call ZL/VK0LD/MM on their journey from Heard Island to the port in Fremantle/Perth in Australia. It is a 39m research vessel. Trust that this answers your question. They are currently in grid OF44 and about a day away from Perth.
Well done on making that contact!
73, Jan ZS6BMN
Would love to see them when they get in. I am in Perth right now.
They are now estimating 0700 Friday Perth time