Some 50 cruise ships sail to Antarctica each year. There are rules laid down by the International Association of Antarctic Tour Operators covering such things as the size of cruise ships allowed to enter Antarctic waters and covering conduct at landing sites in Antarctica. One of the main rules is that only 100 passengers at one time may land in any one place in Antarctica. If your are one a small ship of up to 100 passengers, then you may get a chance to go ashore every time. If the ship is larger, then there will be fewer opportunities for landings.
Visitors to the Antarctic region visit mostly during the summer months, to view glaciers, icebergs, and some of the whale species to be found in these waters, including the Humpback, Killer Whales and Minke Whales. Also among the icebergs, glaciers and mountains are other whales such as the Fin and Sei, all of which make for spectacular viewing. Penguins trekking over the massive ice flows is a real joy as well as it is to experience the unique and ancient snowscape first hand.
Cruise ships departing from Ushuaia basically follow three itinerary routes. The short route of typically 7 to 10 nights takes you to the Antarctica Peninsula and will most likely stop at one of the South Shetland Islands as well. One of the drawbacks of the short itinerary is you have to cross the sometimes stormy Drake Passage twice. It is 650 kilometers (400 miles) of open sea between South America and Antarctica.
The Mid-length itinerary typically has a duration that average 11 nights or so. This route will take you to the Falkland Island as well the places of the short route, and only has one straight across trip through the Drake Passage. On the long-route itinerary, South Georgia Island is added to the mid-length route. Cruises are normally 14 to 20 nights, though some last four weeks. The rugged South Georgia Island is renowned for its spectacular wildlife.
With average mid-summer temperatures (December to February) ranging from -6C to +10C (20F-50F), it is the most pleasant and comfortable time for tourists to visit. The peak season is from mid-December to mid-February, with long daylight hours and calmer seas. Wildlife viewing is at its best, both onboard and on shore. This is the prime penguin egg-hatching season, and the fluffy chicks are adorable. The peak season is also where prices for Antarctica cruises are at their highest, and many cruises are booked six or more months in advance.
The early season is from November to mid-December. At this time of the year icebergs and iceshapes are at their dramatic best, but the sea ice may not have sufficiently melted, making some landings inaccessible. Weather is colder and seas somewhat rougher. The late season is from mid-February to March. Whale watching is at its best, but penguins are more rarer since they are leaving their breeding grounds to go to sea to feed. There is also less ice, allowing ships to sail to destinations further south, although temperatures gets appreciately colder and daylight hours shorter and shorter.