Mangrove Kayak & Snorkel Tour, St. Thomas: Paddling to Cas Cay
If you want more than a boat drop-and-snorkel, the mangrove kayak snorkel tour on St. Thomas is the most hands-on half day on the island. You paddle across a protected marine sanctuary to deserted Cas Cay, hike to its blowholes and tide pools, then snorkel a healthy reef before paddling back. Here's exactly how it works and who it suits. (Comparing water trips? See all the St. Thomas snorkel tours on the homepage.)
About This Activity
Up to 24h in advance — full refund
Lock in your date, pay nothing today
Kayak, hike and snorkel combined
Stable sit-on-top kayaks, no experience needed
Short trail to blowholes and tide pools
Gear included; calm, shallow site
Check Live Availability & Prices
Real-time dates and prices for the Cas Cay kayak, hike and snorkel tour.
Why Paddle to Cas Cay
Cas Cay sits inside the Mangrove Lagoon and St. James Marine Reserve on the southeast side of St. Thomas — a protected sanctuary you can only reach by small boat or kayak. That protection is the point: the mangroves are a nursery for young fish, so the reef just offshore is unusually alive, and the cay itself is deserted.
You launch from a calm, sheltered lagoon, so even first-time paddlers are fine. Guides lead the whole way, point out the wildlife threading through the mangrove roots, and carry the snorkel gear, so all you do is paddle, walk and swim.
What You'll See on the Trip
The tour packs three different ecosystems into one morning. Across the paddle, hike and snorkel you'll typically find:
- Mangrove channels acting as a fish nursery — baby barracuda, snappers and upside-down jellyfish
- Cas Cay's volcanic shoreline, blowholes and tide pools on the short hike
- A shallow fringing reef with sea fans, parrotfish and the occasional turtle or ray
- Pelicans, herons and hermit crabs around the deserted cay
Because the snorkel site is shallow and sheltered behind the cay, visibility holds up even when the open coast is choppy.
What's Included (and What's Not)
Included
Your guide, gear and the whole half-day are covered:
- Guided kayak through the Mangrove Lagoon sanctuary
- All snorkel gear (mask, snorkel, fins) and a flotation vest
- Guided hike on Cas Cay to the blowholes and tide pools
- Bottled water
Not included
Hotel transfers to the launch point aren't included — it's near Compass Point Marina on the East End. Bring reef-safe sunscreen, water shoes or sturdy sandals for the rocky hike, and a waterproof phone case. Gratuities for the guide are optional.
How the 3 Hours Flow
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0:00
Meet & launch
Quick safety and paddle briefing, then launch into the calm Mangrove Lagoon.
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0:30
Paddle the mangroves
Guided kayak through the sheltered sanctuary channels to Cas Cay.
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1:00
Hike Cas Cay
Beach the kayaks and hike to the blowholes and tide pools on the deserted cay.
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1:45
Snorkel the reef
Snorkel the shallow fringing reef just off the cay with your guide.
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2:30
Paddle back
Return paddle to the launch, back on land by early afternoon.
Important Things to Know Before You Book
You don't need kayaking or snorkeling experience, but you should be comfortable with light physical activity — about 30–40 minutes of total paddling plus a rocky hike. The trip runs in most conditions because the lagoon is sheltered, but it's weather-dependent and free cancellation up to 24 hours out keeps booking low-risk.
It's a small-group, nature-first tour rather than a party boat, so it suits travelers who want to actually see the ecosystem. Cruise passengers should confirm their ship's all-aboard time, since the East End launch is a 25–30 minute taxi from the Charlotte Amalie docks.
Where It Happens
Who This Trip Is (and Isn't) For
Great for active travelers, nature lovers and families with older kids who want a hands-on half day instead of a crowded beach. It's less ideal for:
- Anyone who can't paddle 30+ minutes or manage a rocky, uneven hike
- Travelers wanting a relaxed boat trip with an open bar
- Very young children who can't sit safely in a kayak
Cas Cay Kayak & Snorkel FAQ
Do I need kayaking experience?
No. The lagoon is calm and sheltered, the sit-on-top kayaks are stable, and guides lead the whole way and help with technique. If you can paddle gently for half an hour, you're fine.
Is the snorkeling any good?
Yes — because Cas Cay is a protected sanctuary, the shallow reef is healthier and fishier than many easier-to-reach spots. It's calm and shallow, which also makes it beginner-friendly. Compare it with the boat-based reefs on our snorkel tours homepage.
What should I wear and bring?
Swimwear, water shoes or sturdy sandals for the rocky hike, reef-safe sunscreen, and a waterproof phone case. The blowhole hike crosses sharp volcanic rock, so flip-flops aren't ideal.
Where does it leave from?
From the East End near Compass Point Marina — about a 25–30 minute taxi from the Charlotte Amalie cruise docks.
Is it good for kids?
Older kids who can swim and handle a short hike do well. The paddling and rocky terrain make it a bit much for toddlers.
What Paddlers Say
Way more interesting than a regular boat snorkel. We paddled through the mangroves, hiked to a blowhole, then snorkeled a reef with almost no one else around. Our guide knew every fish.
The Cas Cay reef was the best snorkeling of our trip and we basically had it to ourselves. Bring water shoes — the hike is rocky but worth it.
Small group, great guide, and a real workout in the best way. Kids loved the tide pools and we saw a turtle while snorkeling.