Port Jackson, famously known as Sydney Harbour, is a large, iconic estuary in New South Wales, Australia. It is a major working waterway characterized by significant commercial and recreational vessel traffic, including ferries and naval vessels, which paddlers must constantly navigate. The harbour is bounded by the heads at North Head and South Head, and its waters include the Parramatta River, Middle Harbour, and Lane Cove River. For paddlers, the experience offers world-famous views of landmarks like the Sydney Opera House and Harbour Bridge from a low, intimate water-level perspective, particularly striking during the early morning civil twilight period. The overall character is one of a bustling marine transport corridor where a small craft must maintain high situational awareness and visibility, accepting that the route is dictated by real-time conditions rather than offering unimpeded access.

Launch points are numerous around the harbour's extensive shoreline. Specific put-ins include Lavender Bay on the northern shore, from which paddlers can explore nearby bays and venture to Goat Island. Middle Harbour, accessed from points like Mosman, is a more protected paddling area with gentle morning conditions, leading under the Spit Bridge and into the narrowing harbour towards Garigal National Park. Key hazards include the constant presence of large vessel traffic and the need to understand ferry lanes and restricted zones. A sunrise paddle, while offering a quieter surface, does not grant priority over other harbour users. Personal watercraft (jet skis) are prohibited anywhere on Port Jackson, including all its tidal bays and tributaries, which reduces one source of traffic conflict for paddlers. The harbour is a saltwater estuary with significant tidal flow. Winds can generate fetch across the harbour's broad sections, but Middle Harbour offers more sheltered conditions. There is no surf zone at the heads being a common paddling route, indicating most recreational paddling occurs within the protected harbour basin. Recommended routes include a 10-kilometer return trip from Lavender Bay exploring northern shore bays and Goat Island, taking approximately 2.5 to 3 hours, and eco-tours from Sydney Harbour Kayaks that journey into Middle Harbour. The water body holds deep historical and cultural significance as Aboriginal Country and a focal point of colonial settlement, with sights like the historic Quarantine Station adding to the paddling experience.