Key West

For the most reliable boat-day conditions, plan for April through July. Seas are often steadier, and water is warm enough for long reef dives and snorkeling sessions. Late summer (August) can be very warm, often near 30°C, and mornings can be calm, but it overlaps hurricane season. Winter (December through February) is still diveable, yet cold fronts can bring wind and chop and cooler water closer to 22°C, which can limit wreck trips and make crossings rougher.

Dry Tortugas is almost 113 km west of Key West and is only reachable by permitted ferry or seaplane. Reserve early because seats are limited and weather can cancel trips. Pack reef-safe sunscreen, a rashguard, water, and snacks, and bring your own mask if fit is critical. Most day trips focus on Fort Jefferson plus snorkeling in shallow water around 1 m to 5 m. Confirm what is included (park entrance fee, snorkel gear, lunch) and put the trip early in your itinerary so you have a backup day if seas are too rough.

The USS Vandenberg is a large wreck and conditions can include current and deeper profiles than nearby shallow reefs. Many operators recommend at least Advanced Open Water or equivalent experience, plus good buoyancy and situational awareness. Plan your profile based on the charter's briefing, but expect wreck structure to start around recreational limits and the deeper parts to reach roughly 30 m to 40 m. If you want to enter openings or swim-throughs, get proper wreck training and follow local rules. Nitrox can help on multi-dive days, but only use it with training and an analyzed cylinder.

Several Key West reefs sit inside Sanctuary Preservation Areas (SPAs) within Florida Keys National Marine Sanctuary. For visitors, the big impact is that you can dive and snorkel, but you cannot take marine life, and you must avoid any contact with coral or the bottom. Many sites use mooring buoys to prevent anchor damage, so boats tie in rather than anchor on reef. If your group also fishes, know that some zones have additional restrictions. Your operator should brief the zone for the day, but you are still responsible for following the rules.

Pack exposure protection based on season and your cold tolerance. In late summer, water can hover near 30°C, and many divers are comfortable in a 3mm or even a skin for short dives. In winter, cold fronts can drop water toward 22°C, and a 5mm is common, especially for multiple dives per day or long snorkel sessions. Bring a hooded vest if you get cold easily. Regardless of season, a rashguard helps with sun protection and reduces the need for heavy sunscreen.

Key West diving is boat-based, so seasickness prevention matters. Book the earliest departure you can, since seas often build later. The day before, hydrate and avoid heavy alcohol. On the boat, stay in fresh air, watch the horizon, and keep your mask and fins ready so you are not lingering in the heat. If the forecast calls for strong wind (for example, 40.2 kph or more), choose a shorter run or a shallow reef day instead of a long wreck crossing. If you use medication, test it on land before your trip so you know how it affects you.

For urgent problems, call 911. Key West has hospital care via Lower Keys Medical Center, and it is the first stop for serious injuries, breathing problems, or suspected decompression illness. If you think you have DCS, do not wait it out. Stop diving, keep warm, and seek medical evaluation immediately. Divers Alert Network (DAN) can help coordinate diving medical advice and referrals through their 24/7 hotline (+1-919-684-9111). Travel with your insurance details and a list of medications, and tell your operator about any concerns as early as possible.

Yes. Many travelers fly into Miami (MIA) or Fort Lauderdale (FLL) and drive the Overseas Highway to Key West. From Miami it is about 258 km, and the trip becomes part of the vacation with bridge and water views. If you prefer to skip the drive, the Key West Express runs a high-speed ferry from Florida's west coast (Ft. Myers Beach and seasonal Marco Island service). Once in Key West, you can stay car-free if your lodging is walkable and you plan to bike or use taxis and rideshares.

Start by asking how the operator handles sanctuary rules. Good signs include a clear reef briefing, strict no-touch expectations, and routine use of mooring buoys instead of anchoring on coral. In the Florida Keys, NOAA runs the Blue Star recognition program for operators who commit to visitor education and responsible practices. You can also ask about group size, in-water guides, and whether they avoid overcrowding the same mooring. Finally, choose trips that match your skill level. Overchallenging divers is bad for safety and bad for reefs.

Build the schedule so everyone wins. Let divers take early boat departures, then meet non-divers for brunch and an Old Town walking loop. Put a mangrove eco tour on a windy day when offshore boats might be rough. For a shared highlight, plan Dry Tortugas as a full-day outing: history at Fort Jefferson plus clear shallow snorkeling around 1 m to 5 m. Evenings are easy to share: sunset, casual seafood, and live music. If you are staying a week, add a rest day mid-trip to keep energy high.