The world‘s finest diving

Nautilus Under Sea

At 95 feet (29 meters), Nautilus Under Sea isn't the largest but in terms of comfort, she equals the rest & she is a true diver's dream boat. Socorro & Guadalupe itineraries.

A word from Dom : “The original liveaboard of the Undersea Hunter Group in Cocos became Nautilus Under Sea a few years ago, taking divers to Socorro & Guadalupe. She is the favorite of many divers (myself included) for her intimacy & comfort level and never fails to amaze her guests. Everything is as close to perfection as it gets. She well deserves her long-standing fabulous reputation.”….. Dominick Macan

Under Sea Ext island opt 1

On Board Nautilus Under Sea

1 upper deck DOUBLE / TWIN premium suite
king bed or 2 adjacent double beds & picture windows
1 main deck TWIN cabin (disabled friendly)
2 twin beds & picture windows
1 main deck TRIPLE cabin
2 bunk beds (used only for 3 people) & porthole
6 lower deck TWIN / DOUBLE cabins
1 double bed, 1 twin bed (bunk style) & porthole

All are en-suite & have individually controlled air conditioning

Socorro up to 4 dives per day
(depending on sea conditions)
Guadalupe, unlimited cage dives
12 liter alu tanks (INT valves,no DIN valves)
15 liter alu tanks (at extra cost)
scuba gear rental (by advance request)
nitrox & rebreather support (request in advance)
water temperature: 73 – 82F, 23 – 28C … 5 – 7mm wetsuit recommended

accommodation & diving
meals, snacks & non-alcoholic beverages
compressed air, tanks, weights and weight belts
use of sea kayaks
(except at Guadalupe)
a lounge area in a local hotel until boarding time
round-trip transfers from the hotel to the boat

international & domestic airfare
airport transfers to & from the hospitality suite
alcoholic beverages
optional wifi
Aqualung rental gear (please request in advance)
nitrox, re-breather support & steel tanks
15 liter tanks
port fee & possible fuel surcharge

A New Life & A New Look In Socorro & Guadalupe

Beginning in October 2016, the much beloved Undersea Hunterof Cocos Island fame underwent a massive refit and became Nautilus Under Sea. Her mission now is to carry divers to revel in the magic of the mantas, sharks and whales of the magnificent Revillagigedo Islands (including Socorro) off the western coast of Mexico. She also offers cage diving with great white sharks at Guadalupe Island.

For your non-diving hours the boat offers a large sundeck with lounge chairs & a hot tub on the upper deck (bridge deck). The covered portion here, just behind the bridge, has great sofas that you can snuggle into – particularly inviting when the weather is a bit blustery … also table & chairs an the all-important bar,

The entire main deck is now wheelchair accessible including dining room and lounge, large new stateroom, head and dive stations …. with a ramp down to the lower swim platform. The Nautilus team love the idea of making the great white sharks and giant mantas more accessible for handicapped divers.

In the salon, you’ll find plenty of entertainment including, a multi-system television and VCR, CD stereo, slide projector, DVD player and multimedia laptop computer for your use. The back half of this deck is devoted to diving and camera area while in the front, there’s a triple cabin … and from the bow, you can enjoy vistas of sunsets, approaching islands or dolphins surfing the boat’s bow wake. The remaining 6 cabins are located on the lower deck.

You can expect a fusion of Mexican and North American food with fresh baking, produce and vegetables. If you have special dietary needs, please let us know at time of booking. The chefs will make every effort to meet your requirements.

Travel & Cruise Logistics


You have two options for airports for your Guadalupe adventure.You can fly into the San Diego airport (SAN), and then proceed to the Nautilus San Diego Dive Center. Alternatively you can also fly into the Tijuana airport (TIJ).

If meeting the Nautilus team at their San Diego Dive Center, they will load baggage and depart at 7:30 pm for the approximate 2 hour transfer to where your ship will be waiting for you in Ensenada, Mexico. Mexican custom regulations require all guests exit the vehicle at the border with their belongings, obtain a tourist card and then walk through customs before boarding the vehicle again. The Nautilus staff will help you with this procedure.  Alternatively, guests may also meet the Nautilus team directly in Ensenada, Mexico. If you are meeting them directly in Mexico and you are not a Mexican citizen, you must stop and get an FMM.

At the end of your cruise the ship normally arrives back at Ensenada approx. at 2:00PM. Arrival time is always subject to weather and may be later. Guests who met the crew in Ensenada will be be transferred back to Tijuana Airport in Ensenada. Guests who met them in San Diego will be transferred back to San Diego Dive Center or San Diego Airport. The coach typically arrives in San Diego by 7:00 PM. Please do not book return flights earlier than 9:00 PM.


You will fly into the San Jose del Cabo airport (SJD), and then proceed to the Nautilus dive center at the Tesoro Los Cabos in Cabo San Lucas. There you can leave your bags and then tour town and enjoy a nice dinner before boarding the ship. The crew is working hard right up to boarding time to get the ship ready so please meet them at the hospitality suite and not at the boat.

On the final day disembarkation is at 8.30am for transfer back to San Jose del Cabo airport (SJD). We recommend that you book your return flights for 10:00 AM or later.

Layout & Specs

View the deck & cabin layout


Length: 105 feet (32 meters)
Beam: 24 feet (7 meters)
Built: USA
ISM safety certified
18 guests, 9 ensuite staterooms & suites
Internet access & satellite phone
Caterpillar engine power
Air fills, nitrox, rebreather friendly


Nautilus Under Sea itineraries include the Revillagigedo Islands; San Benedicto, Socorro & Roca Partida in addition she makes trips to Guadalupe Island.

Socorro (November – May)
8-night Socorro trips are typical.  Specific itinerary will be subject to weather conditons each day but will almost always include San Benedicto, Socorro & Roca Partida.


You can expect to dive with giant mantas with wingspans up to 20 feet. They accept your presence in their habitat and seem to approach divers seeking contact. The experience is spine-tingling.  You may also see up to 10 varieties of shark: from schooling hammerheads, to Galápagos sharks, whitetip reef sharks, silver-tips, silkies, tiger sharks and oceanic whitetips. The list also includes whale sharks and dusky sharks and on occasion even a thresher shark.

A typical 8-night itinerary follows

Day 1 – boarding begins at 8pm in Cabo San Lucas
Day 2 – at sea … arrival at San Benedicto in the evening. You’ll have a briefing and cocktail hour before dinner.
Day 3 – San Benedicto  (3 – 4 dives, depending on conditions)
Day 4 – Socorro Island – 3 dives + evening snorkeling with silky sharks under flood lights
Day 5 – Socorro Island (3 – 4 dives, depending on conditions)
Day 6 – Roca Partida (4 dives)
Day 7 – Roca Partida
Day 8 – at sea … return to Cabo the next morning

Undersea Map Socorro opt

Guadalupe  (August – October)
5-night trips to Guadalupe with 3 full days of cage diving.

Guadalupe is simply the best destination in the world for calm clear water and consistently high probability of multiple shark encounters per day.

A typical 5-night itinerary follows

Day 1 – meet in San Diego at 7:30pm …. bus ride to Ensenada …. boarding at 9:30pm
Day 2 – at sea … arrival at Guadalupe in the evening.
Day 3, 4 & 5 – cage diving from 6:30am to dusk
Day 6 – at sea … arrival at San Diego at 7:30pm


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