Update March 5: Video from El Archo
I was fascinated by that idea since there are a few challenges associated with this - challenges that you don't have when flying from shore. Interestingly enough, the things I thought would be more challenging turned out to be less of an issue but other problems started to emerge and become challenges.
The boat we got was a simple one, with a canapé spread across the top. This provided us with welcomed shade, but also meant less room for taking off and landing. Plus, it turns out, it also obstructed our visual views of the flying machines a little. But since we were prepared to fly FPV via monitor and goggles, this wasn't a big issue. Except when coming back and landing...
The biggest challenge; after 20 minutes of being in the air, our little boat drifted pretty far away from the location I took off from. However, the telemetry data doesn't know that and shows you the home location where the quadcopter took off from. Coming back to that location revealed no boat being there! Or a different boat having taking our previous spot. So that made it very interesting. Luckily I had planned enough time and power for landing and so it took some time to locate us and then come in for a landing. Which was another challenge altogether.
Since the boat is moving and there is not a lot of space to land, Randy volunteered to be the catcher. I decided to land coming into the wind. That made it easier for me as I actually had to push the controls to make it come towards Randy and if something happened, I could just let go of the sticks and it would not smash right into him - the wind would not push it into our good helper.
Mark did a fantastic video flight and when following the Diamond (the Diamond on the screen shows you where the system saved the launch location and is a very helpful orientation tool) on the screen to come home, he also learned that our boat had left "home".
It was fun flying it that way and I have gotten used to the "black" screen every two seconds when it takes a picture. I start to blink to the rhythm of that shutter occurrence and it becomes less noticeable. However, what becomes more noticeable are the waves and the rocking of the boat: motion sickness... flying with the goggles on a boat really gets to me!
I did a quick test flight to see how the signal would hold up on the other side of the arch and then it was Mark's turn to fly straight through it.
Mark decided to fly visually and let me use the goggles for navigation and feedback. He is really good at using geometry as his guide. And sure enough, the Phantom 2 was heading towards the arch, 3 meters (9 feet) of the water. The arch was approaching quickly and I could see all the boats on the other side through the goggles. Also on the other side was a large rock formation pointing out and Mark managed to fly very close by it, pulling up and gaining altitude so the video signal would not get interrupted by the entire rock formation.
He parked the Phantom in the sky, handed me the controls, grabbed a beer and said "My job here is done! You bring her home!".
Update: Here is a short video of our adventure at the arch!