
moderate
5 hours
Moderate fitness for paddling 1–2 miles, a short rocky hike, and swimming while snorkeling; suitable for active beginners.
Paddle sheltered mangrove channels, hike to volcanic cliffs and a pulsing blowhole, then snorkel clear reefs around Cas Cay on this 5-hour guided tour of St. Thomas’ marine sanctuary. Expect hands-on natural history, wildlife sightings, and an easy-paced outdoor day with lunch included.
The paddle begins like a slow conversation between you and the water: narrow channels of mangrove roots frame a strip of sky, sunlight falling in broken beams, and the guide taps the bow to point out a small silver flash — a juvenile tarpon weaving under a prop root. Kayaks slide through the lagoon with a quiet confidence; the mangroves seem to lean in, leaves whispering. Later you trade paddle for trail: a short hike to volcanic cliffs where a blowhole huffs seawater like a distant drum, and then you slip into a reef world, fins slicing into blue, searching for rays and coral gardens.

Guides emphasize reef protection — choose mineral-based sunscreen and reapply in shaded breaks to protect coral and marine life.
Kayak landings and the short cliff hike include sharp coral and rocky sand — closed-toe water shoes protect feet on wet, uneven surfaces.
Channels are usually calm but the open-water snorkel can be choppy; take anti-nausea meds an hour before departure if sensitive.
Bring a waterproof phone case or drybag—pockets and loose items can slip out during launches and snorkeling.
Cas Cay and surrounding reefs have been protected as part of a marine sanctuary to rebuild fish stocks and preserve mangrove nursery habitat crucial to local fisheries.
Tours emphasize low-impact practices—use reef-safe sunscreen, avoid touching coral or animals, and follow guide instructions to minimize reef disturbance.
Protects your skin and the reef; required by most guides.
Protects feet during landings and the short rocky hike.
Blocks wind on open-water sections and is useful during brief tropical showers.
summer specific
Keeps valuables dry during kayak launches and snorkeling.