The four factors
Shore time and ratings are weighted higher because they are measured, not opinion — they carry more of the score precisely because they carry less editorial risk.
The shore-time formula, worked
Shore time is derived from a single public constraint: IAATO caps any shore party at 100 people. A ship's effective Antarctic capacity, divided into that limit, produces a score out of 100 — capped at 100, and set to zero for any operator that makes no landings at all.
Lindblad Expeditions, effective capacity 137.3: 100 ÷ 137.3 × 100 = 72.8
Poseidon Expeditions, effective capacity 114: 100 ÷ 114 × 100 = 87.7
"Effective Antarctic capacity" is not the same as a ship's total berth count. Scenic Eclipse carries 228 berths but is limited to 200 in Antarctic waters; Silversea's Silver Cloud and Silver Wind carry 254 but are limited to 240. This site uses the Antarctic-specific limit in every calculation, never the ship's total berth count, because the total berth count overstates how many people actually compete for a shore slot on any given landing day.
Where an operator runs more than one ship, effective capacity is the mean across the fleet — but only across ships that are actually comparable. Oceanwide's average excludes the 33-berth Rembrandt van Rijn sailing vessel, which carries no ice classification, from the average of its three ice-classed motor ships (Hondius, Ortelius, Plancius). Folding a non-ice-classed sailing vessel into the same average as ice-classed expedition ships had handed Oceanwide the single highest shore-time score in the entire ranking — a result driven by a category mismatch, not a real operational advantage, so the sailing vessel comes out of the average rather than being averaged in.
Two capacity figures in this dataset carry a documented, unresolved discrepancy rather than a single clean number: National Geographic Orion is listed as 102 guests by Wikipedia and as a 102–106 range by CruiseMapper, and this site could not resolve the difference against Lindblad's own current page. National Geographic Resolution's capacity was resolved to 138 guests from Lindblad's own live ship page, superseding an earlier figure of 126 still found on some third-party sell sheets and travel-agency sites. Both are stated openly rather than silently picking whichever figure was more convenient.
The composite score, worked in full
The four factors combine as a weighted sum. Using Poseidon Expeditions as the example:
shore_time = 87.7 · rating_points = (4.75 ÷ 5) × 100 = 95 · price_value = 75 · expedition_depth = 80
total = (0.35 × 87.7) + (0.30 × 95) + (0.20 × 75) + (0.15 × 80) = 30.7 + 28.5 + 15.0 + 12.0 = 86.2
Sorting all ten operators descending on this total reproduces the ranking on the homepage exactly. The order is a consequence of the inputs, not a separate decision — change any operator's capacity, rating or price data and the order recalculates.
What's measured and what's editorial
| Factor | Basis | Weight |
|---|---|---|
| Shore time per passenger | Measured — capacity data, formula above | 35% |
| Traveller ratings | Measured — aggregated third-party ranges | 30% |
| Price & inclusions | Editorial | 20% |
| Expedition depth | Editorial | 15% |
Price/value reasoning, per operator
Editorial price/value scores compare the published price band against what it includes. Oceanwide scores highest (90) as the most affordable segment scored, though it omits a parka. Lindblad scores 60, given the National Geographic partnership's premium — below Quark (65), HX (72), Aurora (78) and Poseidon (75), but above the luxury tier: Scenic (45), Ponant (42) and Silversea (40), whose much higher headline prices are offset by more extensive inclusions in this scoring model. Holland America scores 100 by this measure alone — the lowest absolute price by a wide margin — but that reflects a categorically different product with zero landings, which is why price/value is only 20% of the total rather than the deciding factor.
Expedition-depth reasoning, per operator
Ponant scores highest (95): Le Commandant Charcot is the only Polar Class 2 icebreaker in the world's tourism fleet, with unique access to the Weddell Sea and onboard science labs. Lindblad scores second (92) on full-time National Geographic naturalists and photography instructors. Poseidon scores 80 — a single ship with no helicopters or submersible caps it below multi-ship, aircraft-equipped fleets like Quark's (85) or Scenic's (80, offset by a luxury-first rather than expedition-first design).
How traveller ratings are handled
Ratings are aggregated from Cruise Critic and TripAdvisor as of the publication date shown at the top of the homepage. Where the two platforms disagree, this site prefers the larger sample rather than the higher number. Lindblad is the clearest example: Cruise Critic shows 4.4 across 256 reviews, Travelstride shows 4.8 across 42 — a sample six times smaller. This site uses the Cruise Critic figure and states that choice here, rather than quietly using whichever number is more flattering.
Limitations
- Prices are published brochure ranges per berth, double occupancy, excluding flights to Ushuaia or Punta Arenas and excluding single supplement.
- Fleets and capacities change between seasons; this table is rechecked annually before the season opens.
- Ratings move over time and are refreshed on the same annual schedule.
- No aggregate-rating structured data is published anywhere on this site until a first-party verified review base exists — see the editorial policy.
Requesting a correction
If a figure on this site is wrong or out of date, use the corrections route on the contact page. Include the operator, the specific figure, and a source. See also how operators enter this ranking in the first place: Submit an Operator.