Dive Site: Lone Stone

About Lone Stone

Lone Stone is a small, solitary rock pinnacle emerging from the deep waters surrounding Cocos Island, approximately 550 kilometers off Costa Rica's Pacific coast. This remote site is a magnet for large marine life, thanks to the powerful currents and nutrient upwellings that characterize the Cocos marine protected area. The topography features a rocky formation that acts as a cleaning station and gathering point for diverse pelagic species, offering divers an unparalleled opportunity to witness dense schools of rays and other oceanic predators. The dive experience at Lone Stone is typically a drift dive, following the abundant marine life that congregates around the pinnacle. Depths can vary, but the main action often occurs in the shallower to mid-range zones around the rock, where cleaning stations attract various species. The site is part of the larger Cocos Island ecosystem, a UNESCO World Heritage site known for its exceptional biodiversity and healthy, undisturbed fish populations. Lone Stone provides a clear example of the raw, pelagic action that makes Cocos a world-class diving destination. Encounters with schooling marble rays and mobula rays are frequent, often seen circling the rock in impressive formations. While large pelagics like hammerheads and various sharks are common throughout Cocos, Lone Stone specifically stands out for its ray aggregations. The best months for experiencing peak pelagic action are generally from June to November, although rays are present year-round. This site is exclusively accessed via liveaboard, as are all Cocos Island dive locations, emphasizing its remote and pristine nature.

Dive site facts: Lone Stone

Depth

16–33 m

Current

Strong, unpredictable

Visibility

15–30 m

Water temperature

22–28°C

Entry

Tender / negative entry

Level

Advanced, current experience essential

Dive type

Pelagic, drift

Night dive

Possible, conditions permitting

Region / port

Cocos Island, Costa Rica

Coordinates

5.5, -87.08

Conditions & Currents

Lone Stone is characterized by strong and often unpredictable currents, typical of many Cocos Island dive sites, which are driven by nutrient-rich Pacific upwellings. Divers should anticipate drift diving conditions, where the boat follows the divers' trajectory rather than anchoring. Entry is usually a negative entry, requiring quick descent to avoid being swept away from the site. Exit procedures involve deploying a surface marker buoy (SMB) to signal the boat for pickup, often at a distance from the initial entry point. Thermoclines are common, indicating varying water temperatures at different depths, and visibility can range from 15 to 30 meters, occasionally dropping with increased plankton during peak pelagic seasons. Excellent buoyancy control and experience with currents are essential for a safe and enjoyable dive at this dynamic location.

Marine life & sighting chances

Marble Ray

Year-round, peak June-Nov · common

Mobula Ray

Year-round, peak June-Nov · common

Scalloped Hammerhead Shark

Year-round, peak June-Nov · occasional

White-tip Reef Shark

Year-round · common

Galapagos Shark

Year-round · occasional

Silky Shark

Year-round · occasional

Green Turtle

Year-round · occasional

Moray Eel

Year-round · common

Octopus

Year-round · occasional

Bigeye Jack

Year-round · common

Creole Fish

Year-round · common

Dive profile & how the dive runs

Diving at Lone Stone typically begins with a negative entry from a tender, requiring a swift descent to a suitable depth to avoid being swept away by currents. The dive then becomes a drift along the rock formation, allowing divers to observe the schooling marble and mobula rays that frequent the area. Your dive guide will lead the group, utilizing the currents to navigate around the pinnacle, showcasing the dense pelagic action. Depths will generally stay within recreational limits, often between 12-25 meters, focusing on the zones where marine life is most active, such as cleaning stations. Air consumption is closely monitored, and turnaround is based on gas limits or dive time. The safety stop is conducted as a drift, and divers are expected to deploy a surface marker buoy (SMB) upon ascent to signal the tender for pickup.

Underwater photography

For capturing the abundant schooling rays and pelagic action at Lone Stone, a wide-angle lens is essential. You'll want to be ready for fast-moving subjects in potentially strong currents, so a fast shutter speed is often necessary. While visibility can be good, plankton blooms during peak pelagic seasons might necessitate powerful strobes or video lights to bring out colors and add contrast to the blue water. Maintain excellent buoyancy to avoid stirring up sediment and to position yourself for optimal shots in the current. Always respect the marine life, giving schools of rays ample space and avoiding disruptive behavior that could scatter them. Be prepared for varied lighting conditions, including thermoclines that can affect white balance.

Combine with nearby dive sites

• Dirty Rock

  Known for large schools of marble rays, hammerheads, and tiger sharks.

• Manuelita

  Features a sheer wall, abundant white-tip sharks, and marble rays, with cleaning stations.

• Bajo Alcyone

  A submerged mountain peak famous for large schools of hammerheads and other pelagics.

• Dos Amigos

  An islet with an impressive arch and pinnacle, attracting hammerheads and large schools of fish.

• Viking Rock

  Offers encounters with hammerheads and reef sharks, especially during the dry season.

Getting there & logistics

Access to Lone Stone is exclusively via liveaboard, departing from Puntarenas, Costa Rica. These expeditions typically last 10–12 days, dedicating around seven days to diving around Cocos Island. Due to its popularity and remote location, booking 9–12 months in advance is strongly recommended, particularly for peak seasons. Flights should be booked to Juan Santamaría International Airport (SJO) near San José, followed by a transfer to Puntarenas. Park fees for Cocos Island National Park are additional and usually paid onboard. The itineraries for liveaboards are comprehensive, often including multiple dives at sites like Alcyone, Dirty Rock, Manuelita, and other exploratory dives, depending on conditions.

Safety & environment

Diving at Lone Stone, like all Cocos Island sites, demands a high level of diving proficiency. Divers must be comfortable with strong currents, as drift diving is the norm, and experience with negative entries is crucial. A minimum of 50-100 logged dives and Advanced Open Water certification are usually required by operators. The nearest recompression chamber is located in San José, Costa Rica, necessitating a potentially lengthy and complex evacuation process from Cocos Island. Therefore, comprehensive dive insurance covering medical emergencies and evacuation is mandatory. Divers must always follow the dive guide's instructions, maintain close buddy contact, and carry a reliable surface marker buoy (SMB) for safety in the open ocean. Regular safety stops and conservative dive planning are paramount in this remote environment.

Who it suits — and who it doesn't

FAQ

Lone Stone FAQ

Liveaboards diving Lone Stone

These liveaboards may visit Lone Stone on selected itineraries — the exact dive sites depend on departure, weather and conditions.

Cocos Aggressor

Costa Rica

22 guests37.8 m

$636/day

Sea Hunter

Costa Rica

20 guests

$690/day

Okeanos Aggressor II

Costa Rica

24 guests36.6 m

$504/day