It is one of four straits allowing maritime passage between Buzzards Bay and the Vineyard Sound.

Canapitsit is an Indian word meaning "current passage".

Strong tidal currents (up to 6 knots) separate the islands from each other.

The currents are driven by the different sizes and filling rates of Vineyard Sound to the southeast and Buzzards Bay to the northwest.

The channel is narrow, rocky and subject to strong currents making the passage dangerous.