You can get to Muck by either the CalMac ferry from Mallaig (Monday, Wednesday and Friday during the winter; Tuesday, Thursday, Friday and twice on Saturday in the summer) or the seasonal Arisaig Marine service from Arisaig. During the summer, the Saturday sailings connect with trains to and from Fort William and Glasgow.
Vehicles are not permitted on the island. Muck is about 4km from east to west, and is most easily explored on foot.
In addition to two families offering bed & breakfast, there are a number of cottages available to rent on the island. Details can be found on the Road to the Isles website.