Navigating the Occoquan

The Occoquan Reservoir has nearly 20 miles of navigable water, relatively calm conditions, a world-class 2000-meter race course, and a large and supportive rowing community. Like any river or body of water, the Occoquan Reservoir has many of its own unique features and tendencies, and it can be fairly predictable in its nature. Knowing basic information about the river, as well as what we can expect once we launch for a row, is one  of the first steps that we can take as members to insure that we stay safe and enjoy our time rowing on the Occoquan. Please take the time to review the information below, as well as the map of the Occoquan Reservoir displayed in the OBC boathouse.

Traffic Pattern

All rowers on the Occoquan are expected to follow the established traffic pattern. Be aware that crews from Oxford boathouse may be on the water along with Sandy Run rowers. Always be on the lookout for fishing boats, kayaks, canoes, and paddleboarders. Scullers rowing in groups need not row single file, but they should keep to the proper side of the river.

The general traffic rules are: 

• Proceeding up river, stay to the Fairfax side of the river.

• Proceeding down river, stay to the Prince William side.

• Do not use the “middle third” of the river.

More details regarding the traffic pattern can be found here.

Occoquan Landmarks

The following is a list of landmarks, starting with the furthest downriver and ending with the furthest upriver. These landmarks aid rowers to determine location and communicate that information to others. 

• The Dam: At the furthest rowable point downriver is a large, man-made dam.  This structure is highly visible, and has a long string of orange safety buoys to keep boaters from getting too close. Never attempt to row beyond the safety buoy  line.

• The Racecourse: Between the dam and Sandy Run Park, lies a short, straight  stretch of water that is used as a 2000-meter racecourse in the spring season. Between the months of March and July, buoyed lane lines are installed.

• The Painted Rocks: About ¼ mile upriver from Sandy Run Park is a rocky shoreline on the Prince William shore that has been painted in vibrant, high  school team colors.

• Oxford House: Upriver from the painted rocks is a small inlet on the Prince  Williams shore that leads to a boathouse known as Oxford house used by Prince  William County schools and clubs. 

• Jacob’s Rock/Monitoring Buoy: About 2 miles upriver from Sandy Run is a large rocky outcropping on the Fairfax shore, with “Jacob’s Rock” prominently  displayed in white paint. Mid-river is a large, yellow environmental monitoring  buoy with a bright, flashing beacon. Stay to the right hand side of this buoy. 

• Fountainhead Regional Park: About 3 miles upriver from Sandy Run is a boat  launching area on the Fairfax shore that is part of the NVRPA’s park system. 

• Ryons Dam: About 4 miles upriver from Sandy Run, the remains of a destroyed dam are visible on the Prince William shore. This dam is passable by all boats. Be careful around this structure, as there are still submerged remains that may become exposed when water levels are low. There is a bright red metal stake on top of this portion that will become exposed as the water level drops, warning  when the hazard is closer to the surface.

• The Red House/Monitoring Buoy: A short distance past Ryan’s Dam, a small red, cottage can be seen on a narrow peninsula on the Fairfax shore. Opposite of this house is another environmental monitoring buoy, which can also be used to  direct the flow of traffic on this section of the river. 

• The Picket Fence: About 7 miles upriver from Sandy Run is a large house on the Prince William shore with a long, white picket fence that is highly visible. 

• Bull Run Marina: About 9 miles upriver from Sandy Run, the docks and boat  launching area of Bull Run Marina mark the end of the navigable waters of the  Occoquan. It is recommended that no rowing be done beyond this point.

UNDERSTANDING THE GPS MARKERS

Along the entire length of the navigable river,  there are large, highly visible number signs placed at intervals along the Fairfax shore (Sandy Run side). Painted yellow, orange or red, these signs are known as GPS Markers and are used to give very precise information about locations along the river. It is important to become aware of these signs and know where each numbered GPS marker is along the river. In an emergency  situation, the GPS marker numbers are the best option for giving this information to get help. Here are some examples of how to give good location information using the GPS markers:

• “I am located at GPS marker #11 on the Fairfax shore”

• “I am located between GPS marker #4 and 5# on the Prince William shore” 

• “I am located a quarter mile upriver from GPS marker #9 on the Prince William shore”

REMEMBER: Becoming familiar with these markers will insure that, in an emergency situation,  you are able to communicate clearly where you are to club members, park staff and emergency personnel. 

**A map with the locations of all GPS markers is located in the OBC boathouse**