Our friends place in only a block off the beach, in Puerto Morelos (yep it's nice to have friends like that for sure). It was relatively easy to wake up before sunrise and get ready to see if mother nature was going to reward my efforts to be there.
For Christmas my wife bought me a Pentax O-GPS1. It's main characteristic is to provide GPS coordinates in the meta data. I have found this to work very well and in most cases and places I have used it , it calibrates very quickly. The other feature is it can act as an Astro Tracer. I had not tried this function until we went to Mexico.
While Puerto Morelos is a small fishing town, it is not a certified dark place. Still much better than Cancun or Play Del Carman would be. So far I find it really hit and miss , with way more misses. I think I need to get out to the mountains and give it a try.
What the asto tracer is suppose to do, is based on a calibrated time is to move the internal components of the camera to avoid the star trails. I have seen some incredible photo's of the night sky by others , so to date I am basing the high failure rate on the end user
I would try and arrive on the beach about an hour before sunrise. The conditions have to be right, clear skies , etc and there were at least two days like this. (where I made it out in time - some days too many late night margaritas
)
Of the dozen or so attempts I tried over our time there, this is the only keeper. I hope to get a chance to go out and test again soon.
Specs : DA 12-24 / ISO 100 / 12mm / f4 / 180s taken at 05:23 am (about 30 mins before sunrise)
Click on image twice for larger view