Time tide
From Tardis Wiki, the free Doctor Who reference
The time tides were natural temporal phenomena which connected the temporal shoals to ordinary bodies of water in specific time-zones.
Travellers who chose to sail their timeships on the temporal shoals instead of more guided methods of time-travel would be able to step ashore when the time tide connected to a given body of water, then have to quickly get out, and wait for the tide to come in again to reembark. One notable time-traveller who used the time tides was the Corsair, who sailed the Silver Spray on them. (PROSE: The Bloodletters)
