Cas Cay Snorkeling in St. Thomas: Kayak, Hike & Marine

Three ecosystems in one outing: mangroves, island forest, and coral reef

Cas Cay snorkeling combines kayaking through St. Thomas's Mangrove Lagoon, hiking a pristine island with tidal pools and a rare geological blowhole, and snorkeling in a coral-fringed nursery: all guided, with equipment and instruction included. The 3-hour activity departs at 9:30 AM or 1:30 PM from Virgin Islands Ecotours. Arrive 15 minutes early, and bring a bathing suit, towel, and sun protection.

The experience

You start at Mangrove Lagoon Marina on St. Thomas, where your guide provides a safety briefing and paddling instruction before you kayak among the small red mangrove islands that make up the lagoon. The waterways are shallow and winding: built for exploring at your own pace, with time to watch nesting birds in the trees and spot marine life in the water below.

After paddling, you beach the kayak at Cas Cay, a deserted island in a wildlife sanctuary and marine reserve. The hike is eight minutes each way on a level sandy trail mixed with coral rubble, leading to volcanic cliffs with tidal pools and a rare geologic blowhole where water splashes up through the rock. Your guide points out the thousands of hermit crabs living in the forest. You can even watch them race if you want to try spotting a winner. The cliffs themselves are the payoff: dramatic rock formations and views that make the short walk worth the effort.

Back at the kayaks, you put on your mask, snorkel and life jacket, then snorkel in the coral-fringed mangrove nursery. Colorful fish and stingrays move through the water. The guide shows you creatures and spots you'd miss on your own. Water and snacks are provided throughout. At the marina, you'll find lockers, dressing rooms and toilet facilities to rinse off before you leave. Choose the 9:30 AM or 1:30 PM departure depending on when you want to go.

What’s included

• Water and snacks throughout the activity.
• use of kayak, paddles, snorkel mask, life jacket and mesh bag.
• safety briefing and instruction in kayaking and snorkeling.
• access to lockers, dressing rooms and toilet facilities at the marina.

Options for this experience

2 options

Cas Cay 1:30pmGuide in English · 13:30Explore the Mangrove Lagoon and Cas Cay on this 3-hour kayak, hike, and snorkel tour. It departs from our Mangrove Lagoon Marina at 1:30 pm, so please arrive at least 15 minutes before departure.

Cas Cay at 9:30 AMGuide in English · 09:30Tour

You see the exact price of each option when you check availability.See dates & prices

Before you book

Days and timesEvery dayDepartures at 09:30 and 13:30

Book up to1d before

AgesAdult (13 and older) · Youth (7 to 12 years): free · Child (2 to 6 years)

GroupUp to 40

Live guideEnglish

Meeting point and pickupNo hotel pickup: you go to the meeting point. Ends back at the starting point.

Cancellation and refundsFree cancellation up to 24 h before the start. After that, no refund.It may be canceled due to bad weather or if the minimum number of travelers isn't reached. If that happens, you're offered another date or a refund.

Prices and times updated 3 days ago

Good to know

Moderate physical levelPets welcome

Operated by Virgin Islands Ecotours

Is this one for you?Book the 9:30 AM departure if you want the morning light on the cliffs and prefer starting early. The 1:30 PM slot works better if you're sleeping in or combining this with another activity. Either way, the three-hour span keeps you moving between water and land without long waits, and the guide handles the route so you focus on paddling, hiking and spotting wildlife instead of navigating.

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Top questions

Can children come?

Yes. Ticket types: Youth (7 to 12 years): free; Child (2 to 6 years).

What happens if it rains?

It may be canceled due to bad weather. If that happens, you're offered another date or a refund. Free cancellation up to 24 h before the start.

What's the hike like on Cas Cay?

The hike is eight minutes in each direction on an uneven, level sandy trail mixed with coral rubble, leading to volcanic cliffs with tidal pools and a geological blowhole. It's accessible but requires moderate fitness.

What snorkeling equipment is provided?

Masks, snorkels, life jackets and paddles are all included, along with a mesh bag to hold items that can get wet. Your guide gives snorkeling instruction before you enter the water.

What should I bring and wear?

Bring a bathing suit, towel, shoes that can get wet, and sun protection including sunscreen, sunglasses and a hat. Lockers and dressing rooms are available at Virgin Islands Ecotours to store valuables.

Is transportation to the marina included?

Transportation to Mangrove Lagoon Marina is not included. You'll need to arrange your own way there. Arrive 15 minutes before your departure time.

What time should I arrive?

Arrive at Virgin Islands Ecotours 15 minutes before your tour time. Departures are at 9:30 AM or 1:30 PM.