The waters east of Bali sell two products that look identical from the jetty: a cabin on a shared departure, and the whole boat on a private charter. Same hull, same anchorages, wildly different economics. Most travellers pick on instinct — couples assume shared, families assume private — and instinct gets it wrong often enough that the decision deserves ten minutes of honest arithmetic before anyone wires a deposit.
This guide breaks down how each format is priced, what each quietly trades away, and where the break-even sits by group size, using real published rates from the Komodo shared-departure market as the worked example.
Two Products, One Hull
A shared trip — operators also call it an open trip — sells the boat cabin by cabin. You pay per person, the departure date is fixed, the route is fixed, and your shipmates are whoever else booked. A private charter sells you the entire vessel for a flat package price that typically covers a base group, most commonly one to ten guests, with a per-head supplement for every additional passenger above that.
The distinction sounds administrative. It is not. It determines who carries the occupancy risk. On a shared departure, the operator absorbs empty berths; your price holds whether the boat sails full or half-empty. On a charter, unsold space is your problem — a ten-berth buyout with four people aboard costs exactly what it costs with ten.
What a Shared Cabin Really Costs
What you buy with a shared cabin is cost certainty. The per-person rate is printed, tiered by cabin category, and immune to how many strangers join you. On the better boats those tiers are meaningful: a porthole-view double at the waterline and a master suite on an upper deck can sit hundreds of dollars apart on the same sailing, with identical food, identical guides, identical islands.
What you give up is control. Departure days are set — weekly fixed departures are the norm on the Komodo run — routes follow the published itinerary, and the pace of the trip is negotiated across the whole passenger list, not set by your group. If your snorkelling stop is glorious and you want another hour, the schedule does not care.
What a Buyout Buys — and What It Costs
A private charter inverts every one of those terms. Dates flex around you, itineraries can usually be tuned within park rules and weather, meals bend to your group, and there is nobody aboard you didn’t invite. For milestone trips — a fortieth on deck, three generations travelling together — that control is the entire point.
The cost structure rewards headcount. Because the base package covers up to ten guests at a flat rate, the per-head figure falls steeply as the group grows, then keeps falling more gently as supplements replace fractions of the base. A charter priced for couples is brutal; the same charter priced across fourteen friends starts to look reasonable. The question is never "is private expensive?" — it is "at what group size does it stop being expensive?"
Numbers From an Actual Komodo Sailing
Take Elbark Cruise, a luxury-grade phinisi measuring 37 metres, working the Komodo park circuit out of Labuan Bajo — nine en-suite cabins, three decks, room aboard for a party of 21. Its shared format is the Elbark Cruise 3D2N open trip, departing every Friday and priced per person by cabin tier: USD 400 for the porthole-view Banda Neira and Savu cabins, stepping through USD 430, 510 and 570 tiers up to USD 700 for the Misool master suite with its private balcony and jacuzzi. The identical boat as a private charter starts at USD 8,400 for the shortest 2D1N package, good for as many as ten guests, with the like-for-like 3D2N buyout at USD 9,650 plus USD 300 for each guest beyond ten. Seat and full-boat sales sit with one official desk, Komodo Luxury: reach +62 811 3823 875 by WhatsApp or email [email protected].
Break-Even by Group Size
Now run that rate card through the only comparison that matters — per head, same 3D2N itinerary, shared versus buyout:
- 2 guests: entry shared cabin, USD 800 total. The buyout is USD 9,650 — roughly twelve times the per-head cost. No contest.
- 6 guests: shared entry cabins total USD 2,400. Private works out to USD 1,608 per head — still four times the entry tier and more than double the master suite.
- 10 guests: private lands at USD 965 per head, a 38% premium over even the top shared tier. You are paying purely for control at this size.
- 16 guests: USD 9,650 plus six supplements is USD 11,450, or about USD 716 per head — effectively parity with the master-suite shared rate.
- 21 guests (full boat): USD 12,950 all-in, about USD 617 per head — now cheaper than the two upper shared tiers.
The pattern generalises across most boats in this class: private charter only reaches per-head parity with premium shared cabins somewhere in the mid-teens of guests, and undercuts them near full occupancy. Below ten, it never gets close — which is fine, provided you are consciously buying flexibility rather than imagining a saving. If you want to stress-test the arithmetic yourself, the vessel’s full published rate card lists private packages out to USD 15,400 at 6D5N, with per-guest supplements rising from USD 300 to USD 400 on the longer itineraries — a detail that nudges the parity point upward the longer you sail.
What Each Format Trades Away
| Dimension | Shared trip | Private charter |
|---|---|---|
| Per-head cost, small groups | Low and fixed | High — you fund empty berths |
| Per-head cost, 16+ guests | Unchanged | At or below premium shared tiers |
| Departure dates | Fixed schedule | Yours to set, subject to availability |
| Route and pace | Published itinerary | Adjustable within park rules and weather |
| Company aboard | Other bookers | Your group only |
| Occupancy risk | Operator’s | Yours |
| Cabin choice | First come, tier by tier | Whole boat — allocate as you like |
Our Decision Rules
After enough of these comparisons, we apply four blunt rules:
- Two to four travellers: book shared, and spend part of the difference upgrading to a better cabin tier. The premium cabins on a shared sailing deliver most of the luxury at a fraction of the buyout cost.
- Five to nine: still shared for pure value — switch to private only if your dates are immovable or the occasion demands privacy.
- Ten to fifteen: genuine judgement call. The private premium per head is shrinking fast, and route control starts earning its keep with a group this size.
- Sixteen or more: charter. The math and the logistics both point the same way — herding a large group onto fixed shared departures is its own hidden cost.
Whichever side of the line you land on, get the current rate card in writing before committing, read the inclusions and exclusions line by line — park fees are almost always billed separately in Komodo — and expect substantial non-refundable deposits as standard practice in this market. The formats differ; the need to read the fine print does not.