A Time Wake was an anomaly in the Time Vortex caused by the use of (primitive) time travel technology. The Sixth Doctor told Peri Brown it was "rather like the wake left behind by a ship at sea". The duo encountered one created by Tasq, a Time Engineer from the planet Bestonas. It connected London in January 1986 to the London of 1720.
Time Wakes "healed themselves" after primitive time travel excursions were halted. Until that time, however, they presented themselves as shimmering blue-white rings. People could step directly into the rings and be transported to wherever the Wake took them. The sign of a Wake closing was a gradual constriction of the circumference of the ring. It was possible for Time Wakes to be lethal, if one attempted to enter at a point where the circumference could not accommodate one's personal size. Tasq, for instance, died because he tried to step into a Time Wake that had closed too far. (PROSE: Time Wake)
TARDISes additionally left temporal wakes, which were areas in the vortex where it had recently been or would be, meaning a TARDIS could cross its own wake. (PROSE: Imperial Moon) Ramón Salamander believed he had drifted through the Time Vortex in the wake of the Doctor's TARDIS, arriving on Earth only minutes after him in the 1960s, "or perhaps another decade." (COMIC: The Heralds of Destruction, TV: The Web of Fear)
Because she merged with part of his TARDIS, the Seventh Doctor was able to track the wake of the Timewyrm and follow her. (PROSE: Timewyrm: Genesys) The Headhunter programmed Morbius' stellar manipulator to follow the Doctor's TARDIS's time wake as she locked it onto Lucie Miller's DNA. (AUDIO: Worldwide Web) Similarly, the ruptured core of a Dalek time machine left a temporal wake that dragged the Doctor's TARDIS off course. (AUDIO: The Elite)
Due to his actions in the past on Skaro, the Fourth Doctor caused a "timewave" that interfered with the Time Ring and caused himself, Harry, and Sarah Jane to be scattered across the Adelphine Cluster. (PROSE: A Device of Death)