Petaluma River Marathon and Half Marathon

  • Hosted By North Bay Rowing Club



Since 2004, the Petaluma River Marathon has served as the West Coast flat-water marathon/half marathon championship. It is one of the most beautiful and fun races on the west coast. Bring plenty of water and food for the race. There is a beautiful picnic area for the post race potluck BBQ--grills and briquets provided.


The race takes advantage of a unique combination of favorable factors:

Excellent conditions:The water is usually flat at race time, and there is little interference from motorboat wakes. The air temperature is cool at start time. The event is timed on the “river” (actually an estuary) so its direction of flow will favor racers.

Beautiful venue:The picture above of the S curve on the middle Petaluma does not exaggerate the unique character of the river. For most of its course, the river flows through a nature preserve that conveys an impression of pre-Conquest California. In the foreground, the competitors will pass next to native plants and wildlife, and in the background the California coastal range rises to define the horizon.

Fortunate coincidence: The river is almost precisely 13.1 miles from the end of its navigable channel in downtown Petaluma to its mouth at San Pablo Bay. Accordingly, our course, from the NBRC dock to the Highway 37 bridge and back, covers approximately the standard marathon distance. Half Marathon participants will turn at a buoy at the halfway point.


Prizes: Medals for all who complete their event, and special recognition for winning crew of each division.


Eligible Craft: Rowed or paddled craft as follows:

Rowing: Sliding-seat (8+, 4+, 4-, 2-, 4x, 2x, 1x), both flat water and open water designs.

Paddling: Kayaks (both ocean and flat water); surfskis; canoes; 1, 2, and 6-person outrigger canoes; and, for the half marathon only, stand-up paddleboards.


Entry: Register at

All participants must READ and SIGN a waiver (standard USRowing language). Fees prior to Aug 26: $25, $35, $55, $75, and $95 for 1, 2, 4, 6, and 8 person boats, respectively. Fees for late registrants (Aug 26 to Sept 3) are $35, $50, $75, $100, & $120, respectively. There is limited trailer space. Trailer spots will be reserved in order they are requested—Email: Please indicate if you anticipate having space on your trailer for other boats.


THERE WILL BE LIMITED ON RIVER SUPPORT. All participants must be fit and capable of steering a good course and have the experience to safely handle any unexpected problems. First-time participants are strongly advised NOT to attempt the full marathon unless they, including ALL members of the crew, have completed at least one training outing at that distance in less than 4.5 hours. Similarly, SUP entants must be able to paddle 13 miles in less then 3.5 hours.

All crews are requested to carry a cell phone in a waterproof pouch.  Numbers of the support launches and race officials will be distributed before the start and should be programmed in to each cell phone.


Start/Finish Location and Course

There will be a brief participants meeting at 7:00 am. Marathon boats will start at 7:30am, and Half Marathon boats immediately afterwards. The race begins and ends at the North Bay Rowing Club at the south end of 2nd Street in Petaluma California. Enter 38.2314° N, 122.6294° W in the search box on Google Maps to see the start and finish point. Racers can park in the parking lot at Foundry Wharf adjacent to the gate into the North Bay Rowing Club boatyard.


The full marathon (26.2 miles) will begin at the NBRC dock in Petaluma, go downriver 13.1 miles, turn around under the Highway 37 bridge near the mouth of the river, and return to the start. Enter 38.115° N, 122.505° W in the Google maps search window to see the downstream turn for the marathon. Boat should enter third arch from Marin side and return on the fourth. See below.


The half marathon will begin at the same point and turn around at a buoy marking the halfway point (38.1831° N, 122.5437° W).


Traffic Pattern: Participants MUST KEEP STARBOARD NEAR SHORE AT ALL TIMES (especially including turns to port). Be prepared to give way to any tug/barge should one appear.



Tides: In celebration of two of Petaluma’s key economic attributes, ecotourism and artisan food, the moon is lined up to assure ample time to inculcate the wondrous beauty of our tidal wetlands during the opening half of your voyage, then carry you home easily to the shared feast in time to be enjoyed at leisure.   Surely, an experience to be envied by Cittaslow!


For those unsure of reading between the lines, we’ll start toward San Pablo Bay as the tide begins to flood, then ride it home.  The tide will rise as much as five feet, making it easier to carry your boat up from the dock after you finish (you’re welcome).  The particulars:



Low Tide

High Tide











Half Marathon Turnaround





Full Marathon Turnaround






Nutrition and Hydration

The half marathon can be as short as 1.5 hours for a fast double scull to twice that for a recreational paddler in a sea kayak. Double these times for the full marathon. The physical challenges for these distances are linked strongly to your fitness, good nutrition, and critically on race day, ample hydration. Make sure you bring enough food and water. Five quarts or more of water and one to two thousand calories may be necessary during the marathon. Participants are urged to read the excellent essays by Elizabeth Brown, a former national team rower and currently a sports nutritionist at San José State University at


Contact, Info, Questions and Comments


Volunteers needed and encouraged.