Mount McGrath, facing Chatham Sound is a notable feature of the east side of the island.[2]
Tsum Tsadai Inlet is a narrow inlet on the north side of the island, with its opening to the west.[3]
The inlet provides a well protected anchorage for small craft, but should be approached with caution at slack tide, as a group of drying reefs surround the approach, and tidal currents upwards of 5 knots (9.3 km/h; 5.8 mph) are known at the entrance.[4]
To the south of the island is Marcus Passage. To the north is Inverness Passage, separating Smith Island from the Tsimpsean Peninsula.[5] Eleanor Passage, connects Osborn Point, the most eastern point on the island, with the mouth of the Skeena River.[6] De Horsey Passage separates De Horsey Island from Smith Island on the latter's east side.[7] Croasdaile Island is to the south of the southern tip of Smith Island.[8]