A boat that sank in Great Slave Lake south of Yellowknife last month had struck a rock, according to RCMP.

Four people, including a four-year-old child, were rescued by members of Yellowknife's Coast Guard Auxiliary from the 24-foot Maxxum boat.

RCMP got a call about the vessel in distress at about 10 p.m. on July 31. 

sinking boat Great Slave Lake

A boat sinks on Great Slave Lake 24 kilometres south of Yellowknife on July 31. The Coast Guard Auxiliary rescued four people from the boat, including a four-year-old child. (Coast Guard Auxiliary/Yellowknife Unit)

The boat was about 24 kilometres south of Yellowknife on Great Slave Lake when it struck the rock. It lost its propeller and was taking on water in the engine compartment.

The Coast Guard Auxiliary dispatched two vessels, the Nick Martin and the Diavik Discovery.

Police say about 20 minutes after the boaters were rescued, the cabin cruiser was almost completely submerged. It eventually sank.

One boater sustained a minor injury.