I saved and printed their email confirming my booking. Here is a copy:
When you arrive at the North/South Terminal, it does not matter turn right,
walk 100 yards, pass Atlantis Submarines, just a bit further you will see a
parking lot on the Seaside. Wait there. (on the other side is a Church of
God) Look for a white van with SOTOS CRUISES name. Randy/Billy is the
driver. Look forward to hearing from you soon. Thanks.
KERRY, SOTOS CRUISES