Cost is of course very important, and in general, you will find that the larger the ship, the more affordable it is. This is logical: the operational expenses and fixed costs are divided by a larger number, so highly skilled and well-paid crew and expedition teams, not to mention experienced mariners and medical teams, have their salaries effectively divided between more passengers.
Other expenses such as high-grade fuel, insurance and itinerary planning are likewise lower on a per passenger basis.
AE Expeditions' 160-guest Greg Mortimer
Next we should consider comfort. Expedition cruises tend to operate in remote locations and it is not unusual that they will encounter heavy seas - on a larger ship, the motion is less significant.
Likewise a larger ship has space for more hotel facilities (alternative restaurants, spa, fitness, a variety of lounges), as well as the capacity to accommodate a larger and more varied expedition team, bringing you a wider breadth of knowledge and expertise.
Whirlpool on Silversea Expeditions' 200-guest Silver Endeavour
In contrast, the advantage of a tiny ship is that it can access the very smallest bays and lagoons, and in next to no time the full complement of passengers can be off the ship and into the Zodiacs, ready to explore from the moment the anchor is lowered.
In between, we find a whole host of ships carrying 130-260 passengers, and this size brings many advantages, allowing for the combination of a great hotel operation on board the ship, with a stimulating educational experience, laboratories and interactive learning centres.
Zodiacs from Ponant's 184-guest Explorer Yachts in the Kimberley, Australia
Depending on your destination, you will weigh up the considerations. In the Galápagos Islands, for example, the largest licensed passenger vessels have a maximum capacity of 100: nothing bigger is allowed.
Landings around the islands are highly regulated, so you will never share a landing site with other visitors, and you can reasonably expect, whatever size of vessel you choose, to enjoy 3-5 activities a day, ranging from nature walks and hikes ashore to swimming off the beach, exploring the cliffs and mangroves by Zodiac or kayak, or deep sea snorkelling or even diving.
Marina on Silversea Expeditions' 100-guest Silver Origin
In Antarctica, IAATO regulations state that a maximum of 100 people can land at any one time. So on a very small ship everyone can go ashore, and on a slightly larger one, one group will land whilst another goes off to explore by Zodiac or kayak, or sometimes by helicopter or submarine (some expedition ships carry these on board).
Then, in theory, the groups can swap, allowing everyone to land in the morning, and then to navigate to another location enabling everyone to make a second landing in the afternoon.
Kayaking from 228-guest Scenic Eclipse
On a larger ship, more time is needed to land all the guests, which may mean that only one landing a day is possible.
Furthermore, in the polar regions where the weather can change very quickly, there is no guarantee that a promising morning will hold firm long enough for everyone to get ashore. In this case, the organisation is such that the people who were not able to land will be front of the queue the following day - but the experience can be frustrating.
Quark Expeditions' 172-guest World Explorer in Antarctica
