Jack,
I have been monitoring them for the past 5 or so years on 123.500. As 'KCChiefs9690' pointed out, they really do not have much of a need for comms, but there is often a lot of interplane chatter .. manuvering and position, air speed and head wind reports, etc.
I believe that they are operating portable HT equipment as their signal fades fairly quickly. I can usually begin to pick them up when they make the turn NORTH at the inlet and follow them until they turn WEST for the next pickup.
C ya' downey ocean ....