The Firth of Thames is a large, shallow coastal sound on the western shore of New Zealand's Hauraki Gulf. It is a tidal water body, and launching is highly tide-dependent. Several concrete boat ramps provide access, including those at the town of Thames and at Kaiaua, though some ramps may require a tractor or 4WD at very low tides. Other put-in points include the Piako River at Pipiroa, the Waihou River at Turua, and various spots along the Thames Coast Road such as Kawakawa Bay. Paddlers must navigate marked channels when leaving or returning to these river mouths to reach the open Firth. The environment is exposed, with fetch across the sound capable of creating rough conditions, and fog can descend rapidly, creating a significant navigation hazard as evidenced by multiple rescue incidents. The area sees considerable boat traffic, including commercial mussel harvesting barges whose operations attract fish and numerous recreational boats. The coastline features dramatic sea views, pohutukawa-lined cliffs, and quiet coves accessible from State Highway 25. Water clarity is often low near the river mouths, such as the Piako, but clears further from shore. The Firth contains extensive mussel farms, which are prominent features. Safety is a paramount concern, with reports of capsizes, lost paddlers, and the critical importance of carrying communication devices. The water is generally brownish near the inflows of major rivers like the Waikato, Piako, and Waihou.