adjective - A loop course refers to the shape of an open water swim where swimmers swim around buoys in any geometric shape (e.g., triangular or rectangular), generally starting and finishing at the same point which can be in on land or in the water at a fixed position.
The rectangular Olympic 10km Marathon Swim in the Serpentine was a classic loop course.
 Swim Courses
A geometric course refers to the triangular, rectagular or any other multi-side shape of an open water swimming event. It generally has the start and finish at the same point, but not always. The start and finish can be in the water or on land. It can also be referred to as a loop course.
A point-to-point course refers to the shape of an open water swim where swimmers start and finish at two separate points that can be on land or in the water at a fixed position.
An out-and-back course refers to the shape of an open water swim where swimmers start onshore, head out to a point away from shore in a bay, ocean, sea, lake or estuary, and then return back to the finish at the same point where the swim started.