My wife and I made the trip a couple of times in May of 1984 in a sail boat. There is a key about half way betweek Key West and the Tortugas which makes a good place to stop over night. A lot may have changed since 1983, but at that time, there was a lagoon in the middle of the key, with a deep channel entering on the east side. We had no problem entering the lagoon in a 4 foot draft sail boat. It made a perfectly protected anchorage to spend the night in. The anchorage at the Tortugas is fairly large and about 25 feet deep. You are going to need at least 200 feet of line to anchor safely. Best if you have some chain at the anchor end, because the bottom is sand with a lot of broken coral. The wind blew like h.... really hard, most of the time we were there. There were LARGE whitecaps in the anchorage. You need to pay a lot of attention to your anchoring technique if you want to sleep at night. Use a lot of line and a heavy anchor. There is no water, no food, no anything in the Tortugas. Take twice as much food and water as you think you will need. If the wind picks up, you might be stuck there a couple of days longer than you planned. Have fun. Wish we were going.