A cruise down the River Thames has been included on the syllabus of past summers spent on the program in London. Valuable to understanding the geography of London, the cruise allows students to not only view the many famous landmarks located along the banks of the river, but also the layered architecture, the relationship between the north and south banks, and the importance of the river to shaping the city, to commerce, and as a method of transportation. Though the cruise reaches its destination at Greenwich, London, where the Prime Meridian is located, the boat travels past a reconstructed version of William Shakespeare's Globe theatre, St. Paul's Cathedral, the Tower of London, the newly opened Tate Modern, Canary Wharf, and the Millenium Dome. Passage underneath various bridges, among them, the London Bridge is especially exciting. The ride to Greenwich is approximately an hour in length, enabling students to relax while stimultaneously realizing the sprawling size of the urban centre.

Once arrived at Greenwich, students collectively tour the Maritime Museum and Chapel. Afterward they are excused to explore the town, but are encouraged, if not expected, to travel through Battersea Park to the Royal Observatory, the site of the Prime Meridian. The Prime Meridian of the World, or Longitude 0°, is the "north-south line selected as the zero reference line for astronomical observations." The line provides a constant site from which astronomical observations may be taken in order to compose an accurate map of the sky. It also divides the eastern and western hemispheres, making it a particularly entertaining point-of-interest. The Prime Meridian serves as the reference line for Greenwich Mean Time. The line measures or sets time, thus standardizing it internationally.