The British show "Doc Martin" is available on Netflix as of March of 2015. At that time, Netflix was the only streaming service that offered the sixth season of this British show.
Apple's iTunes allows users to download season six of "Doc Martin," but the service does not offer users the ability to stream the episodes online. Amazon.com allows for Prime members to stream the previous five seasons of the program for free; they can also download the sixth season for $2.99 an episode.
The sixth season of "Doc Martin" consists of eight episodes. This is the same length of season as the previous two seasons. Before that the length of season varied; the show aired only six episodes in its premiere year.