Snorkeling Trunk Bay
Swim Past The Underwater Trail

Snorkeling Trunk Bay is definitely the most well-known on St John. The beach is beautiful and so are the turquoise waters. Though it is not dense, there is some coral life to see here and a decent number of fish, making the snorkeling good, but not great.

Note: This page is a sample from our popular St John Snorkeling Guide eBook available here.

Snorkeling Trunk Bay, the view from above
Trunk Bay Underwater Snorkeling Trail Map
One of the underwater trail plaques we found

Offshore near the right end of the beach is an island called Trunk Cay, famous for its underwater snorkeling trail. When we visited, the signs for the trail were overgrown and unreadable, though we assume they clean them periodically. Because the trail is close to shore and well used, there is not much of the coral and sea life left that is being described on the plaques. To really see anything, you need to swim well past the end of the snorkel trail. Read more below.

Trunk Bay and Trunk Cay are exposed to winds coming from the north, including the northeast. Also, if the winds are strong from the east it will be too rough to swim and the currents will be strong on the east and north sides of the island. So, consider visiting some other spot if the winds are up from those directions.

In addition to folks visiting St. John, Trunk Bay Beach is the destination of many cruise ship visitors coming over from St. Thomas, so the beach and parking area are usually crowded.

It is the only national park beach with an entry fee, $4 when we visited. The beach offers full facilities, including lifeguards.

The sandy water entrance for snorkeling Trunk Bay

Water Entrance

The water entrance for snorkeling Trunk Bay is sandy. We noticed that the beach is slightly steep which means you need to keep an eye out for breaking waves.

Where To Snorkel

There are three basic areas you can explore snorkeling Trunk Bay.

Red Hind Grouper trying to hide in a sponge

On the far right side of the beach you can swim along the rocks. There are a few corals, sponges and fish to see here. It gets less healthy the farther out you go toward the point, and the visibility goes down too.

The island, Trunk Cay, has snorkeling all the way around it. You will see signs on the beach warning that if you swim around the island the lifeguards cannot see you. This is of course at your own risk. Make sure it is calm enough to even attempt it. The approximate distance around the island is 2000 feet, not a short swim. So be sure you are up for it. If not, stay on the left (looking from the beach) side of the island.

The soft coral garden on the left side of Trunk Cay

Snorkeling Trunk Bay along the right side of the island, it is mostly rocks and a good number of fish. As you approach the far point of the island, it gets deeper, and you start to see more corals. For us the visibility improved and was very good near the point.

As you round the point and start heading back to shore on the left side of the island the bottom drops off and is rocky, down to 20 feet in depth. The topography is fairly interesting. Along the left side, just after the point, you will find a nice patch of healthier soft corals and some hard corals. There are less fish on this side, but many sponges and tunicates. This is where the best corals are for snorkeling Trunk Bay. This side of the island is generally much busier with other snorkelers because it is more protected from the east winds and waves.

As you get closer to shore you will start to see the underwater trail plaques.

Snorkeling the left side of Trunk Bay Beach

You can also snorkel the far left side of the beach, along the rocky shore, heading for Jumbie Beach. Be careful here as this area is more exposed to waves and can have some current. Unfortunately, next to shore you will find a dead Elkhorn Coral reef that now has very sparse mostly unhealthy corals, and we saw few fish. Slightly offshore there are patch reefs of Lobed Star Coral, most of which are dead too.

Overall we experienced decent visibility, with some areas being very good. The depths for snorkeling Trunk Bay ranged from 1-20 feet.

What We Saw Snorkeling Trunk Bay

We found a generally unhealthy reef with some areas of live corals, including nice soft corals, sea plumes, sea rods, etc. We saw many sea fans too but most looked unhealthy. There were many groupers, including Rock Hinds and Coneys and large Yellowtail Snappers obviously begging for a handout. We also encountered large schools of jacks swimming by quickly.


Colorful Stoplight Parrotfish
  • Angelfish, French
  • Butterflyfish: Banded, Foureye
  • Damselfish: Night Sergeant, Sergeant Major, Threespot
  • Filefish: Orangespotted, Scrawled
  • Goatfish, Yellow
  • Goby, Cleaning
  • Grouper: Coney, Red Hind
  • Grunt: Bluestriped, Caesar, French
  • Hamlet: Butter, Yellowtail
  • Jack: Bar - large school, Yellow - large school
  • Lizardfish, Sand Diver
  • Parrotfish: Queen, Redband, Redtail, Stoplight, Striped, Yellowtail
  • Porgy, Sheepshead
  • Silversides
  • Snapper: Gray, Lane, Mutton, Schoolmaster, Yellowtail
  • Squirrelfish
  • Surgeonfish: Doctorfish, Ocean
  • Tang, Blue
  • Trumpetfish
  • Trunkfish, Smooth
  • Wrasse: Bluehead, Puddingwife, Slippery Dick
One of the large schools of jacks that sped by us around Trunk Cay
Pillar Coral and Sea Plumes at Trunk Cay

Coral - sparse and in small amounts:

  • Brain: Grooved, Knobby, Maze, Symmetrical
  • Corky Sea Finger
  • Elkhorn
  • Encrusting Gorgonian
  • Finger
  • Fire: Blade, Branching
  • Golf Ball
  • Lettuce
  • Mustard Hill
  • Pillar
  • Sea Fan: Common, Venus
  • Sea Plumes
  • Sea Rod: Bent, Black, Porous and others
  • Star: Greater, Lobed, Mountainous
  • Starlet, Massive

Painted and Blue Bell Tunicates also known as sea squirts

Other Creatures:

  • Anemone, Giant
  • Feather Duster Worm: Magnificent, Split Crown
  • Flamingo Tongue
  • Sponge: Black Ball, Brain, Ircinia, Red Blister, Rope, Strawberry, Vase, Yellow Tube
  • Tube Worm, Christmas Tree
  • Tunicate, Painted
  • Urchin: Long Spined, Rock Boring, West Indian Sea Egg
  • Zoanthid, White Encrusting

Driving Directions

  1. From Cruz Bay, head north out of town on Route 20/North Shore Road.
  2. You will pass the Caneel Bay overlook, the turn into the Caneel Resort and then go around and pass by Hawksnest Bay.
  3. Before reaching Trunk Bay, there is a small parking area for Jumbie Bay on the right.
  4. The left turn into the Trunk Bay parking lot is signed. If you want to have an easy time finding a parking spot, get there before 8:30am. It fills up.
Trunk Bay sign and parking lot. Get here early, it fills up fast!
Trunk Bay restroom building

This park has full facilities. There are bathrooms, shower rooms and foot showers. There are many picnic tables in the shade with barbecues you can use and trash cans. There is a beach and snorkel gear rental place, a small store with basics, and a little grill snack shop. On the beach there are lifeguards.



Now check out Waterlemon Cay

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