Indeed it does. There are two important numbers to keep in mind:

1. If a ship carries more than 500 passengers, there will be no landings.
2. No more than 100 people ashore at the same time.

If a ship carries 101 to 500 passengers, they'll be divided into groups of no more than 100. One group will land. As it starts to return, the next group will start to land, and so on until everyone has gone ashore and come back. A ship with 450 passengers won't be able to do more than one landing a day, or perhaps two at nearby sites (but most sites aren't close enough to others for this to be practical). A ship that carries fewer than 200 will often be able to land at two sites the same day, especially in Antarctic summer when evenings are long. A ship with fewer than 100 will have even more flexibility in this regard.

If you're interested in overnight camping on the ice, and your ship is toward the high end of the size range for landing, sign up early. The number of passengers who camp will be capped at about 80 to keep the total number of people who go ashore, including crew members, from exceeding 100.