Destinations
Costa Rica • Liveaboard guide • Checked September 2026
One extraordinary island.
Which boat is right for you?
Compare Cocos Island Aggressor, Okeanos Aggressor II and Sea Hunter by cabin, trip length, fare and the extras that shape your real budget. Start with the boat that fits how you travel, then compare matching departure dates.
Disclosure: booking links are affiliate links. Divezone may earn a commission if you book through them. This is a researched comparison, not a first-hand review or a live availability feed.
Cocos Island boats at a glance
Swipe or scroll horizontally on smaller screens. Prices below are reference fares per person, not all-inclusive quotes. USD and EUR figures are deliberately labelled separately and must not be ranked as equivalent prices.
| Compare | Cocos Island Aggressor | Okeanos Aggressor II | Sea Hunter |
|---|---|---|---|
| Guests / cabins | 22 guests / 12 cabins | 22 guests / 11 cabins* | 20 guests / 10 cabins |
| Length | 138 ft (about 42 m) | 120 ft (about 37 m) | 115 ft (about 35 m) |
| Cabin choices | Deluxe twins; upper-deck Master twins or queen; 2 dedicated Solo cabins | Deluxe bunk layout; Master queen; 2 suites with twin or king beds | Lower-deck twin or double cabins; 2 upper-deck suites |
| Bathroom & comfort | Private bathroom; individual air conditioning | Private bathroom; air-conditioned cabins | Private bathroom; air conditioning |
| Trip length | 10 nights in the 2026 rate table | 10 nights; selected 8-night trips | 10 or 11 nights on listed itineraries |
| 2026 fare reference | US$6,849 Deluxe / 10 nights | US$6,399 Deluxe / 10 nights | €6,315 / 10 nights, 20 October 2026 listing; shown full when checked |
| Other cabin reference fares | Master $7,199; Solo $8,849 | Master $6,749; Suite $7,249 | Request the exact cabin and departure quote |
| Nitrox | Available at extra cost | Available at extra cost | Included for certified divers |
| Internet | Paid packages; connectivity varies | Paid packages; connectivity varies | Starlink: $50 through agents; included on direct operator bookings |
| Main reason to shortlist | Dedicated Solo cabins and side-by-side Deluxe beds | Lower published 10-night Deluxe fare; suite options | Smaller guest capacity and included Nitrox |
| Watch before booking | Solo cabin price is higher than a shared Deluxe berth | Check bed layout and current deck plan* | Confirm park fees, fuel surcharge and complete inclusions |
| Availability | See Cocos dates & prices → | See Okeanos II dates & prices → | See Sea Hunter dates & prices → |
Aggressor fares: published 2026, 10-night rates; shared cabin basis except the dedicated Solo category. Sea Hunter: a dated partner listing, not a bookable offer or an annual tariff. *Okeanos II’s official specifications and numbered cabin list indicate 11 cabins, while its introductory paragraph is inconsistent. We use the detailed plan; confirm your cabin number when booking. Operator specifications take precedence over conflicting reseller descriptions.
Choose around your priorities
Start with Cocos
A dedicated Solo cabin gives you a clear option for private accommodation. Compare its fare with shared-berth availability and a sole-use quote on the other boats.
Compare Okeanos II
Its published 2026 Deluxe fare is $450 below Cocos Island Aggressor for 10 nights. Check promotions on both boats and whether the bunk arrangement suits you.
Look at Sea Hunter
Included Nitrox can change the comparison once extras are added. Ask for an itemised quote before deciding that a higher headline fare means a higher final bill.
For couples: reserve the exact bed arrangement. A cabin category name does not guarantee a double bed. For friends: distinguish side-by-side twins from an upper bunk. For photographers: ask about charging points, camera storage and space for your actual equipment before paying.
What does a Cocos trip really cost?
Compare the same year, duration, occupancy and currency. A shorter cruise may have a lower ticket price while giving you fewer days at the island. Use this checklist with every quotation:
Cabin fare + mandatory park fees and taxes + fuel and evacuation charges + Nitrox or equipment rental + flights + hotels and transfers + insurance + optional internet and gratuities.
Aggressor, 10 nights: the current travel sheet lists a $490 park fee plus 13% VAT ($553.70), a mandatory $30 evacuation-plan charge and a $150 fuel surcharge for departures from 1 July 2026. These listed charges total $733.70 before any further applicable tax or payment surcharge. Ask whether VAT applies to fuel; the sheet also states 13% tax on onboard services and a 3% card surcharge on park fees. This is not a guaranteed final supplement. Nitrox is extra.
Sea Hunter: request the current park charge and any fuel surcharge for your departure in writing; we have not verified a comparable all-in 2026 total. Avoid copying another operator’s fees into this quote.
Reference fares can differ from discounted booking prices. Ask for the deposit, final-payment deadline, cancellation schedule, currency and refund conditions before committing.
Plan the expedition, not just the cabin
Allow roughly 36 hours at sea each way. Travel through San José (SJO) and confirm the designated hotel pickup and Puntarenas embarkation arrangements. Build in hotel time before departure and a buffer after the return; Undersea Hunter recommends against flying home on the day the vessel returns.
Aggressor’s current 10-night guidance indicates approximately 18–21 dives, conditions permitting, with up to three per day and no night diving. Sea Hunter’s published routine also schedules three daytime dives. Ask for the actual days at Cocos on your selected itinerary rather than assuming every night is a diving day.
Currents, surge and variable visibility can make this a demanding trip. Send the operator your certification, recent experience and logged dives so they can confirm suitability and requirements. Confirm the dive-guiding arrangement, required equipment and insurance, including remote evacuation cover. Wildlife encounters are never guaranteed.
What about Argo and older boat listings?
Undersea Hunter currently says Argo is away on a National Geographic Pristine Seas expedition. We therefore keep it outside the main booking comparison until Cocos departures are confirmed. Older online listings for Argo, Okeanos Aggressor I, Undersea Hunter, Inula or Yemaya are not proof of a current Cocos itinerary. Request a dated operator schedule before considering them.
Questions before booking
Which boat is best for a solo diver?
Cocos Island Aggressor has dedicated Solo cabins. For the other boats, ask about shared berths, matching policies and the exact single supplement. Availability depends on the departure.
Which is the cheapest?
Okeanos II has the lower published 2026 10-night Deluxe fare of the two Aggressor boats. A fair three-boat answer requires matching dates, currency, cabin and all mandatory extras.
Will a bigger boat prevent seasickness?
No boat can guarantee a comfortable crossing in every sea state. Consider cabin location and discuss your concerns with the operator before choosing.
Can I book Argo for Cocos now?
Do not rely on a legacy booking page. Obtain explicit confirmation of a recreational Cocos departure from Undersea Hunter first.
Sources & verification
Checked 21 September 2026. Editorial recommendations reflect the stated differences, not a quality ranking. Booking calendars, fees and cabin configurations can change.
- Aggressor: Cocos specifications and rates; Okeanos II specifications and rates; current travel and fee sheet.
- Undersea Hunter: Sea Hunter specifications, trip FAQ and Argo status notice.
- Partner listings: use the boat links in the table for current dates, cabins and prices.
