DIS NURSE,
The ages for the Golden Eagle are 5 and up. You get on the catamaran right down the dock from the Magic -- it was a very short walk. Then you sail on the catamaran for approx 45 minutes to an island. There the catamaran anchors off the beach and you swim over to the beach or put on your snorkeling gear and head out. The beach was very close and the water might even be shallow enough to walk to (although I don't know for sure since we went snorkeling right away). The beach was really nice and the kids on the excursion seemed to really enjoy it. You are at the beach for 1-2 hours (sorry I can't remember exactly). Then you load back up on the catamaran and head back to St. Martin.
I think there were both an am time and a pm time. We went about 1:00 in the afternoon which gave us time to explore St. Martin in the morning. Since we had the late seating for dinner we were in no hurry to get back.
As for seasickness, our catamaran ride was very choppy as there were about 8-10 foot waves and we crashed through them which made the ride rough. We were in the very front of the cat, and we simply held on tight and let the waves hit us straight on. I have to say it was an absolute BLAST! We loved EVERY minute of it!! In fact, there was a 5 yr old girl who was right up front with us and she didn't stop laughing the whole way. She just sat there with her goggles on and yelled "big wave comin' " and then we'd get splashed and we'd all start laughing. There were a few people who did get seasick. We didn't have a problem with it at all even though we were right in the middle of it.
I don't think the seas are always as rough as they were that day. I would imagine it is usually a relatively smooth sailing (as far as catamarans go). We plan on doing this same excursion in April '06. This time we'll have DD 14 and DS 9 with us. We actually are hoping for rough seas as it seemed to add to the excitement. I guess we're a set of thrill seekers!
Sorry for the long post, but I hope I've answered some of your questions.