We're in Cape Coral and have made the trip to the Keys many times. We usually go to Marathon but Key West is about the same distance from Sanibel. When we had a fast boat it was a one day trip. Now that we have a trawler, it's a 2 day trip. We leave Cape Coral and stay in Indian Key Pass at marker 7. It's far enough inside the channel to get protection. It's 9-12 ft and usually quiet, albeit buggy this time of the year. Also, you will probably have cell phone and TV coverage there because you will be close to Everglades City. Watch out for lobster traps. Lobster season opens up on Aug 6 so traps are common off Naples, then it clears till you get about 25 miles from the Keys.