We made ours a two day stay by tent camping out there one night. You would think that sand would be soft to sleep on. Not exactly. It was just one night so no big deal but it was really pretty lumpy and hard.
A high speed catamaran bounced us out some 70 miles to Dry Tortugas National park in winds and 5 foot seas. We had taken our Dramamine, no problems for us.

There is a Fort on the island, it even has a moat around it. Seems a little overkill for a Fort that already has ocean all around it! We saw some odd birds; frigate birds, boobies, noddies and sooty terns. All of them breed on the neighboring unpopulated/undeveloped islands.
Snorkeling was pretty good. We found an area scattered with buttons or small zones of coral. It is amazing the little micro communities that develop in even a little patch of coral.
The constellations seemed to pop out of the sky
The Tortugas are a great place for dark night sky. The stars were beautiful and the milky way shown bright. It was black dark except for stray light from boats mored off-shore. It is well worth another visit. Maybe with a kayak next time…and we will hope that the seas will cooperate. I’d dump one for sure in 5 foot waves.