1) Why is there a 2000 MOCA out over the ocean?

Are there perhaps offshore installations of some sort? Weather
stations? I know MOCA's are 1500 on the Q-routes over the Gulf, since
the oil platforms are sometimes 400+ ft tall at the tallest (antenna)
points.

2) Why do the MEA's around PREPI get lower as you get further from
the VOR?

I would like to know what MEA's mean offshore in the first place. The
MEA's on the Q-routes are 6000 ft. Why? They're not VOR based. You
can't get anything like consistent radio reception at 6000 (or 11000
for that matter) - you're always given lost comm instructions and relay
through airliners. There's no RADAR coverage. So why 6000 and not
2000? Haven't figured it out yet.

Michael