Only a few larger cruise ships operate on Galapagos. They are almost all of the luxury class, which means that the service and food are of the best quality. These are ships of more than 16 passengers. The largest take up to 100 passengers. Obviously there is more crew on board. There are several guides, because they go ashore in small groups so as not to disturb nature. These ships usually have cabins of different categories. They sail faster than a small ship so that they can also visit the more distant islands. They are also more stable – that means less risk of seasickness. The medical facilities are better (on some ships there is always a doctor on board) and the peripheral activities are more extensive: there are various lounges, conference rooms, facilities for children, etc. Large ships are sometimes chartered by companies or large groups.