Enough people have noticed now that it makes sense for everyone to cotton on to what they've found. There's some square yellow boxes in the back with wave symbols on them. It looks like it could be equipment that you could use in a situation like this, and sure enough, if you grab one and jump with it, it self-inflates to let you land in the water without fear of sinking or losing your equipment.
As for the cloud, it's up and out, and doesn't even turn around once to see what havok it's caused. For your part, you're in the water, about 150 feet from the shore of the island. You're about a half mile from land, so there's really only one good choice: the island.
Once you've dragged yourselves to the shore of the island, you can survey your surroundings. The main gate of the complex is plainly visible about twenty yards up from the shore. A gravel path leads up the double security doors. On either side of the path, is a nicely trimmed hedge. Above the doors, a red light flashes, with the word "Quarantined" plainly visible.
The island itself is about 750 feet in diameter, and roughly egg shaped, with you on the more angular side of the egg. A pier extends about 50 feet out into the water from this end of the island. The complex itself is only one floor, and is about 100 feet on a side. The portion of the island that the complex does not occupy is covered with scrub brush, and the occasional small tree.