James Loreto - Chain Bridge to Mount Vernon

Chain Bridge (Washington, DC) to Mount Vernon (Virginia)

33 km (20.5 miles)

11 hours, 40 minutes on 3 October 2019

Observed and documented by Lisa Throckmorton

First swim from Chain Bridge to Mount Vernon.



  • Name: James Loreto
  • Gender: male
  • Age on swim date: 47
  • Nationality: United States
  • Resides: Bethesda, Maryland

Support Personnel

  • Christian Lamanna - pilot
  • Josh Heizelmann - crew, backup kayaker
  • Jon Gaul - kayaker
  • Lisa Throckmorton - observer

Observer qualifications: Swam Chesapeake Bay Swim, MIMS Relay, Vermont Kingdom Swims (very familiar with observation rules).

Escort Vessel: 17’ Sea Doo Challenger (Lusby, MD)

Swim Parameters

  • Category: Solo, nonstop, unassisted.
  • Rules: MSF Rules of Marathon Swimming, without exception or modification.
  • Equipment used: Textile jammers, goggles, cap

Route Definition

Starting 0.3 miles north of Chain Bridge. Must swim on west side until key bridge for enough water to swim, Must follow east side of Roosevelt island (not enough water on west). Must swim around navigation aides around at National airport (pics show this and route), through West side opening of Wilson Bridge (for safe navigation), and must swim through navigational aides into Mount Vernon at finish.

  • Body of Water: Potomac River
  • Route Type: one-way
  • Start Location: 0.3 miles north of Chain Bridge (large rock) (38.932611, -77.117696)
  • Finish Location: Beach next to Mount Vernon Wharf, Virginia (38.705120, -77.088668)
  • Minimum Route Distance: 33 km (20.5 miles)


No known previous swims of this route. Swim completed simultaneously with Denis Crean.

Swim Data

  • Start: 3 October 2019, 09:34:57 (America/New_York, UTC-4).
  • Finish: 3 October 2019, 21:15:40
  • Elapsed: 11 hours, 40 minutes, 43 seconds.

Summary of Conditions

Feature Min Max
Water Temp (F) 74 78
Air Temp (F) 74 78.5
Wind (mph) 10 10

GPS Track

Trackpoint frequency: 30 minutes. Download raw data (CSV).

Speed Plot

Nutrition: UCAN + electrolytes, every 30 minutes

Observer Log

Download PDF


by Jim Loreto

Swimmers and Crew Getting Ready: Christian Lamanna, Jon Gaul, Josh Heizelmann, Lisa Throckmorton

THE DMV (District, Maryland and Virginia) is home for me and “a river runs through it.” I grew up in Bethesda, MD on the edge of DC and spent time on all parts of the Potomac. From hiking up near the rapids at Great Falls to taking my boat out for 4^th^ of July celebrations on the Potomac to tubing with my kids between Memorial Bridge and the tidal basin. I have always been amazed at the under-usage of this great body of water. There have been a few events here that have included some swims in the DC portion, but the Potomac gets a bad rap that it is not clean enough to swim.

Fast forward many years and I have gotten into marathon swimming. I met Denis Crean who runs Wave One OWS at National Harbor to discuss an upcoming swim I had of the Catalina Island Channel that I heard he completed. We met for breakfast and a friendship was formed. He gave me great advice, but most of the conversation was about our mutual love of the Potomac and all the waters around us from the Chesapeake Bay to the Atlantic Ocean. We shared so many ideas and thoughts for marathon swims in these waters. One that stuck out to both of us, was a deep desire to do a swim from the northern Potomac (near Chain Bridge) where the water rapids end to at least 20 miles down stream. This was 2017 and we continued to talk, plan, and think through the logistics. We also had an idea to put the Potomac on the Map as “swimmable” and that we could create a Marathon Swim here.

Step 1 would be to get permission to do the swim ourselves. We got a permit from Harbor Patrol, after scouting our route by boat and by charts over months of and meetings and practice swims. We gathered a great crew that included two boats with crews and kayakers and other open water swimmers to ensure the safe passage. We picked a two-day Window for weather October 3^rd^ and 4^th^, 2019.

The first date was a Thursday on purpose to lesson the boat traffic and October made sense as the boating was dying down. We got lucky and the weather for October 3^rd^ was around 76 degrees air tem and the water about the same. (Honestly a little hot in my opinion for that long of a swim). We had an east wind (better than North!) of about 10kts that made more of a difference in the wider parts we swam. Lastly we planned around the tides. In the upper Potomac high tide was 12:30pm and ended at 8:30pm. However, the tide would change near the finish around 6:00pm and our goal was to finish before 7:30pm sunset and without too much of the tide hitting us.

We decided to start at 9:30 am to swim against the tide by Chain Bridge for the first three hours while feeling fresh and with narrow water. We had done a few test swims and noticed up there the tidal shift didn’t offer much resistance that far north. Further challenging the swim was almost zero rain for 30 days, making and tidal flow minimal. We timed going against and with the current (per mile) in practices with only a few minutes apart in speed. What we realized is that with only a max of 6 hours of any sort of assist, there would be almost equal swim against any tides as with it. We had no idea what to really expect but this was an adventure.

My swim felt great at the beginning..finishing my first mile at 23 minutes which is fast for me and felt strong and the water seemed to be moving even though the tide was still low and not flooding. As the hours went by, I really enjoyed the scenery. From all the monuments and bridges to aircraft flying over head. I had a few bad “miles” in the middle” due to the wind and the waves and honestly felt pretty bad. Once I crossed the Wilson Bridge into Maryland waters things seemed to start to shift a little and my times dropped and so did my mental and physical energy. Soon we realized around 4pm that my swim would end as a night swim. We were prepared and I added a clip on light, the kayaker added glow sticks and so did the boat in addition to navigation lights. There was a beautiful sunset as I rounding the corner toward the straight path into Mount Vernon. I didn’t anticipate the tides crushing me the last two miles in the dark. Took 57:09 for mile 19 and 1:13 for mile 20…wow.

Denis waited for me on the Beach for my Finish. 1st DC Marathon Swim in the Books!

In the end it was a really hard swim but I loved it. Different pushes and pulls and waves and currents, but so proud to be a part of a first swim like this and complete full circle on that first conversation with Denis. Denis did incredible finishing almost two full hours ahead. I am proud to have had a chance to swim together as the first two swimmers on this path. We hope to promote clean water in the Potomac and show that the Potomac River is open for swimming.

Swim to Honor Cap

Last…who I swim for…I swim to honor the lives of those lost who have given the ultimate sacrifice in defense of our country. Specifically, my classmates from the Naval Academy class of 1995. I wear a special cap and provide my team with shirts as a way to honor those lives. I am affiliated with a group called Run to Honor and an offshoot called Swim to Honor. Every stroke that hurts I am reminded of their sacrifice.

Driving to starting Point with crew rocking our Swim to Honor Shirts


Click to enlarge.