Smooth Island forms the southwestern side of the Minnicog Channel. The island is 0.2 miles (0.32 km) southwest of Minnicognashene Island.[2] It is approximately 180 metres (590 ft) above sea level.[3] Numerous shoals are in the vicinity of the island.[4]
Since 2012, Smooth Island has had a small bay with a sandy bottom. This bay has persistently low water levels.[5] The island is 1400 yards long and 350 yards wide. Its height is 20 yards.[4]
Smooth Island has some sparse woods.[2] A bay on the island has dense populations of bulrushes, grasses, bushes, and reeds, which are able to grow there due to the low water levels.[5] There are a number of small rocks on the southeastern side of the island. Additionally, dry rocks extend almost 0.6 miles (0.97 km) beyond its northwestern edge.[2]
Some rocks near Smooth Island include Mohawk Rock and Skylark Rock.[4]
