Umpqua River South Jetty

Winchester Bay sits at the mouth of the Umpqua River in Douglas County, and the south jetty there is the primary jetty dive on Oregon's south coast, centered on the rock armor of the main south jetty and a shorter auxiliary structure called the Triangle Jetty. The site is reached from the end of Salmon Harbor Drive. That shorter auxiliary structure shelters a pocket of water that stays almost calm even when the outer sea is violently rough, which makes it the fallback when conditions close everything else out. Reported visibility across the site runs from about 5 to 40 feet.

The modern jetty system at the river mouth was built in stages, with the north jetty completed between 1923 and 1927 and the south jetty finished in 1935. Salmon Harbor at Winchester Bay grew alongside the jetty era into one of the largest recreational marinas on the Oregon coast, with Umpqua Lighthouse State Park on the north headland above the entrance. There is no dive shop or air-fill service at Winchester Bay itself; the nearest public fill sits roughly 85 miles south at Port Orford.

The jetty stone and its invertebrate cover give the site a rocky reef biome, and the exposed outer edge together with the adjacent sand beach add a surf zone biome across the same shoreline. Scuba and spearfishing are the documented uses here. Strong tidal current at the river mouth makes slack the safer window for the outer rock, and the Triangle Jetty pocket serves as the sheltered option when the outer bar is running.

Free paved parking is available at Douglas County's South Jetty County Park at the end of Salmon Harbor Drive, with additional roadside pullouts along Salmon Harbor Drive and restrooms on site. The dry-sand beach south of the jetty falls inside a Western Snowy Plover Management Area, and dry-sand foot travel there is restricted from March 15 to September 15, though wet sand and the jetty rock itself stay open through the closure. No marine reserve overlay applies at the jetty, and take is enforced under standard Oregon Department of Fish and Wildlife recreational marine rules; abalone remains closed statewide.