Dive Site: Lobster Rock

About Lobster Rock

Lobster Rock is a volcanic rock formation located off the northern coast of Cocos Island, distinguished by its finger-like shape and surrounding white sand. This site offers a relatively tranquil environment compared to other Cocos Island dive locations, as it is somewhat sheltered from strong surface conditions, though currents can still be swift at times. Its name originates from the numerous lobsters, including Pronghorn, Royal, and Painted Spiny Lobsters, found within its cracks and crevices between 12 to 20 meters deep. The topography also includes a nearby rhodolith-covered plateau to the north, which hosts the endemic Cocos rosy-lipped batfish. While primarily known for its crustaceans, Lobster Rock is teeming with diverse marine life across all depths. Shallow areas are home to various bottom dwellers, while mid-water sections frequently feature pelagic species. This site is often combined with the nearby Ulloa dive site, allowing divers to explore both areas in a single dive. The protection offered by its location makes it a reliable alternative when other sites, such as Alcyone, are too challenging due to strong currents or surface conditions. It's a prime example of the rich biodiversity of Cocos Island beyond just large pelagics, offering excellent opportunities for both macro and broader marine observations.

Dive site facts: Lobster Rock

Depth

5–33 m

Typical dive

12–20 m, 50–60 min

Current

Mild to swift

Visibility

15–30 m

Water temperature

22–29 °C (with thermoclines)

Entry

Tender

Level

Intermediate to Advanced

Dive type

Reef, deep, big_animals, macro, pinnacle

Night dive

Not possible

Region / port

Cocos Island

Coordinates

7.7984° N, 86.1822° W

Conditions & Currents

Lobster Rock generally offers a more tranquil environment compared to many other Cocos Island dive sites, benefiting from the calmer seas on the north coast. However, divers should be aware that currents can still be swift at times, potentially leading to drift on ascent. The site is a popular gathering spot for whitetip sharks utilizing cleaning services, which implies consistent but manageable water movement. Visibility at Lobster Rock typically ranges from 15 to 30 meters, with potential for up to 30 meters. Water temperatures hover between 22 and 29 degrees Celsius, but thermoclines are common, especially below 25 meters, where temperatures can drop significantly. A 3mm to 5mm wetsuit is recommended to account for these temperature fluctuations. Divers should maintain good buoyancy control and be prepared for variable current conditions, particularly when transitioning between differ

Marine life & sighting chances

Pronghorn Spiny Lobster

common

Royal Spiny Lobster

common

Painted Spiny Lobster

common

Whitetip reef shark

common

Frogfish

occasional

Surgeonfish

common

Moray eels

common

Sea turtles

occasional

Giant manta rays

occasional

Spotted eagle rays

occasional

Yellowfin tuna

occasional

Silvertip sharks

occasional

Tiger sharks

occasional

Garden eels

common

Dive profile & how the dive runs

Dives at Lobster Rock typically begin via tender drop-off, often close to the rocky protrusion. The usual plan involves descending to around 12 to 20 meters, where the numerous cracks and crevices harboring various lobster species are explored. The site’s topography, resembling a small finger surrounded by white sand, guides the dive. It is common for divers to explore Lobster Rock in conjunction with the nearby Ulloa site, starting at one and finishing at the other. This allows for a comprehensive tour of the area, including the rhodolith plateau to the north, home to the endemic Cocos rosy-lipped batfish. Throughout the dive, attention should be paid to both the rocky features for macro life and the open water for potential pelagic sightings. The maximum depth can reach 33 meters, but the primary features are shallower. The safety stop is typically conducted as a drift, given that currents can be swift, requiring divers to be mindful of their position and ascent.

Underwater photography

Lobster Rock offers excellent opportunities for both macro and wide-angle photography. For capturing the abundant spiny lobsters and other smaller creatures within the rock's crevices, a macro lens is highly recommended. Pay attention to the endemic Cocos rosy-lipped batfish on the rhodolith plateau, which benefits from focused lighting to highlight its unique features. Wide-angle setups can be effective for schooling fish, such as cottonmouth jacks and surgeonfish, and for showcasing the overall reef structure. Given the potential for thermoclines, careful white balance adjustment or the use of strobes is crucial to maintain natural colors, especially at deeper sections. Due to occasional swift currents, maintaining neutral buoyancy is paramount to avoid disturbing the sandy bottom or fragile organisms. Be respectful of marine life, particularly the spawning black triggerfish and convict tangs at the base of the rock, and avoid intrusive lighting.

Combine with nearby dive sites

• Ulloa

  Often combined with Lobster Rock in a single dive.

• Chatham Bay

  A sheltered site used for checkout dives, known for macro life.

• Manuelita

  Includes channels and outside areas known for sharks and rays.

• Dirty Rock

  An iconic site for hammerheads and other pelagics.

• Shark Fin Rock

  Another Cocos Island dive site frequently visited.

Getting there & logistics

Access to Lobster Rock, like all Cocos Island dive sites, is exclusively via liveaboard cruises, typically departing from Puntarenas, Costa Rica. The journey to Cocos Island takes approximately 36 hours. Liveaboard trips usually last 7 to 10 nights, offering up to 24 dives. Every passenger must pay an additional national park fee, which is around $70 per day plus 13% local taxes, totaling approximately $490 per person for a standard trip duration. The nearest international airport is Juan Santamaría International Airport (SJO) in San José, from which transfers to Puntarenas are arranged. Liveaboards combine Lobster Rock with other iconic Cocos sites such as Manuelita, Dirty Rock, and Alcyone, ensuring a diverse diving itinerary focused on pelagic encounters.

Safety & environment

Diving at Cocos Island, including Lobster Rock, is reserved for experienced divers due to its remote location and the potential for strong currents and thermoclines. While Lobster Rock is relatively sheltered, currents can still be swift, requiring careful ascent planning to avoid drift. Emergency evacuation from Cocos Island is complex and time-consuming; divers must have comprehensive dive insurance that covers emergency medical treatment and evacuation, including hyperbaric chamber treatment. The nearest recompression chamber is located back on mainland Costa Rica. All dives are conducted from tenders, requiring good physical fitness for entry and exit. Divers should adhere strictly to guide instructions, monitor no-decompression limits carefully, and be prepared for water temperature variations requiring appropriate thermal protection, such as a 3mm or 5mm wetsuit.

Who it suits — and who it doesn't

FAQ

Lobster Rock FAQ

Liveaboards diving Lobster Rock

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

Cocos Aggressor

Costa Rica

22 guests37.8 m

$477/day

Sea Hunter

Costa Rica

20 guests

$690/day

Okeanos Aggressor II

Costa Rica

24 guests36.6 m

$582/day