Duffins Creek flows through the Durham Region of southern Ontario, draining from the Oak Ridges Moraine southward through Ajax before emptying into Lake Ontario. The watershed covers approximately 28,300 hectares, and the paddleable lower section offers a calm, flatwater experience through a mix of marsh, creek corridor, and open water.

The primary access point for paddlers is Rotary Park in the town of Ajax, located at the mouth of the creek where it meets Lake Ontario. The canoe and kayak launch is situated on the east side of the creek, with a dock in the west parking lot providing an additional entry option. Paddlers can also put in directly into the water to the left of the dock area. From this launch, two directions are available: heading south under a pedestrian walking bridge to access Lake Ontario, or turning north to paddle upstream. Ajax residents park for free; non-residents pay $10 for three hours or $20 for a full day. The launch area operates seasonally, from spring through fall. Rotary Park itself includes year-round washroom facilities, a pavilion with a concession stand, and picnic areas.

Paddling upstream from Rotary Park, the creek passes through Duffins Marsh, where multiple lookouts offer views of marsh birds and wildlife. The route continues northward past Highway 401 and into more rural, agricultural terrain. A full upstream-and-return paddle from Rotary Park to farm country above Highway 401 and back took one paddling party approximately six hours. The creek is generally calm and well-suited to canoes and kayaks, though conditions near the Lake Ontario mouth can become choppy on windier days, and less experienced paddlers are advised to stay in the sheltered creek rather than venturing onto the open lake.

Wildlife along the creek is varied and frequently encountered. Belted Kingfishers, Great Blue Herons, Gray Catbirds, Northern Cardinals, and Sandpipers have all been observed. Deer, beaver, and mink have also been spotted along the shoreline. In season, salmon runs bring fish activity to the creek, and anglers are commonly found fishing from the banks, particularly in the morning hours. Paddlers should be mindful of fishing lines cast from shore.

Earlier morning hours are generally recommended for paddling, as both the water and parking areas tend to be less congested at that time.