Catherine Breed - Round-Trip Angel Island

Clockwise loop around Angel Island from Aquatic Park

16.1 km (10.0 miles)

4 hours, 14 minutes on 5 August 2022

Observed and documented by Duke Dahlin

Course Record



  • Name: Catherine Breed
  • Gender: female
  • Age on swim date: 29
  • Nationality: United States
  • Resides: Mill Valley, California

Support Personnel

  • Brian Kiernan - RHIB pilot
  • Terry Horn - kayaker
  • Duke Dahlin - observer

Escort Vessel: Dolphin Club inflatable (“Moon”)

Swim Parameters

  • Category: Solo, nonstop, unassisted.
  • Rules: MSF Rules of Marathon Swimming, without exception or modification.
  • Equipment used: Arena one-piece textile swimsuit, Speedo goggles, 1 silicone cap, earplugs.

Route Definition

Start @ Aquatic Park (beach between Dolphin Club and SERC), exit through Aquatic Park opening, clockwise around Angel Island, return to Aquatic Park beach via opening.

  • Body of Water: San Francisco Bay
  • Route Type: island loop
  • Start & Finish Location: Beach between SERC & Dolphin Club docks, Aquatic Park, San Francisco (37.808145, -122.421402)
  • Minimum Route Distance: 16.1 km (10.0 miles) (map).


LongSwimsDB: Round-Trip Angel Island

Note: This swim established a new overall course record - previously held by Dave Kenyon, who swam 4:23 in 1984.

Swim Data

  • Start: 5 August 2022, 05:37:07 (America/Los_Angeles, UTC-7).
  • Finish: 5 August 2022, 09:52:03
  • Elapsed: 4 hours, 14 minutes, 56 seconds.

Summary of Conditions

Feature Min Max
Water Temp (F) 60 62
Air Temp (F) 64 67
Wind (knots) 6 11

GPS Track

Incomplete - missing from start until 6:38am (1 hour, 1 minute).

Trackpoint frequency: 5 minutes. Download raw data (CSV).

Speed Plot

Nutrition: Not indicated by observer.

Observer Log

by Duke Dahlin

I hereby certify that I accompanied Catherine Breed on her August 5, 2022 round trip Angel Island swim. Other helpers were: Terry Horn/Kayaker and Brian Kiernan/AB Inflatable “Moon” Pilot.

Catherine requested that the first feed start after her first hour swim. Following feeds to be every 30 minutes. The feed product was Infinit Electrolyte drink. Also, her main strategy was for all of us to have fun!

1st Hour(5:37am to 6:37am)

The weather conditions weren’t too bad in Aquatic Park Cove. However, as soon as we got out of the cove, the wind picked up.(Wind gust 9-11 mph) Catherine’s stroke rate was 60. Catherine’s a very strong swimmer. The air temp was about 65F. As we approached Alcatraz, the wind started to die down and the water became calmer. At 6:03am I called Vessel Traffic (VT) to advise that Catherine was west of Alcatraz. Towards the end of the first hour, while we were in the middle of the channel between Alcatraz and Angel Island, we encountered a large vessel (the Mediterranean Voyager). At 6:30am VT asked us to stop Catherine to let the Mediterranean Voyager pass. The large vessel MV passed about 150 yards from us. It was a big relief to have the large cargo vessel out of the way. Catherine’s 1st feed was at 6:37am and it took her about 10 seconds.

  • Wind: 9-12mph
  • Water Temp: 61-62F
  • Air Temp: 65-67F
  • Weather Conditions: Cloudy & Overcast, Water Choppy to calm
  • Stroke Per Minute: 60
  • Feeding: 6:37am(One feeding after the 1st hour swim)

2nd Hour(6:37am to 7:37am)

It seems the second hour went by faster than the first hour. There were 2 feedings (each 30 minutes of Infinit at 7:07am and 7:37am. Took Catherine about 10 seconds to feed. Catherine’s stroke rate average 60-64 strokes per minute. Swimming very strong. The weather conditions were unexpectedly great! (Compared to yesterday, 8/4/22) As we approached Angel Island, our kayaker, Terry piloted Catherine close to the shoreline. All along the shoreline, there were curious sea lions checking us out. No encounter with large shipping vessels or any other water craft. Beautiful morning! Reported to VT our location about 7:00am.

  • Wind: 6-9mph
  • Water Temp: 61-62F
  • Air Temp: 65-67F
  • Weather Conditions: Good
  • Stroke Per Minute: 60-64
  • Feedings: 7:07am & 7:37am

3rd Hour(7:37am to 8:37am)

The 3rd hour started off very calm but the wind started to pick up a little. The kayaker/Terry hugged the shoreline on the east side of Angel Island. At 7:42am, the weather conditions improved. The water was calm with just a little breeze. By 7:57am, there was no gust at all. We could see the Bay Bridge, Pier 39, Alcatraz and Aquatic Park Cove. At 8:01am, I called VT to give them an update that we were on the east side of Angel Island. Catherine was able to swim half way between Angel Island and Alcatraz before the 8:37am feeding. The sun was now peeking out from behind the clouds and blue skies started appearing. It felt very tropical out there.

  • Wind: 6-9mph
  • Water Temp: 61-62F
  • Air Temp: 65-66F
  • Weather Conditions: Overcast, Sunshine, calm waters
  • Strokes Per Minute: 64

Feedings: 8:07am & 8:37am([Changed Infinit feeding bottle 8:09am])

4th Hour(8:37am to 9:37am)

During the beginning of the 4th hour, the wind started up again. However, as soon as we passed the east side of Alcatraz, the wind gust started to die off. There were very few water craft on the bay. I called VT at 9:30am to advise we were about a half mile to Aquatic Park Cove and Catherine’s swim would end at the Dolphin Club. Catherine’s stroke rate increase to 68-72 strokes per minute. The end of Catherine’s swim was in sight.

  • Wind: 6-11mph
  • Water Temp: 61-62F
  • Air Temp: 65-67F
  • Weather Conditions: Overcast, Sunshine, Calm Waters
  • Strokes Per minute: 68-72
  • Feedings: 9:07am & 9:37am

14mins & 56 sec

The weather conditions for Catherine’s final 14+ minutes was perfect! Almost no wind, calm water, sunny blue skies…what more can you ask for. Catherine’s stroke rate remained 68-72 strokes per minute as she entered Aquatic Park Cove. Our kayaker/Terry piloted Catherine into Aquatic Park Cove. Brian K./AB operator and I motored back to the Dolphin Club, so I could take photos of Catherine completing her round trip Angel Island swim. I was able to take multiple photos of Catherine as she completed her round trip Angel Island swim. [Catherine finished at 9:51am.]

  • Wind: 6mph
  • Water Temp: 61F
  • Air Temp: 65-67F
  • Weather Conditions: Calm waters, Blue Skies & Sunshine
  • Strokes Per Minute: 68-72
  • Feedings: None

Final Time: 4hr 14mins 56sec

Well done Catherine!

Duke Dahlin/Observer

Original Log

Swimmer Statement

by Catherine Breed

This swim is one of my favorites as it is right in my backyard. I love the soulfullness of marathon swimming and going after a swim that means something to you is special. I did this swim in 2020 in pretty rough conditions and finished in 4:45, I always wanted to come back and do it again in better conditions. This year I swam with a crew of Dolphins for a really solid training effort.

Terry and I planned the swim by choosing a date with good tides and then reached out to Duke to be an observer and Brian to pilot the AB. I have worked with them all before.

The swim went much better than planned. We were expecting to start a little earlier than 5:30 so the 5:37 start was a little late. We also contacted vessel traffic and they told us no ships were coming in the gate but I was not expecting one to be leaving. We waited 4minutes for that boat. On the positive side we were expecting wind to pick up and create rough conditions for the swim back from Point Blunt. It was rough for about an hour but then around Alcatraz into Aquatic Park the winds died.

Overall, we had a great time and good spirits all around.

To be transparent my crew did not double check that both tracking devices were working. I made sure to walk them through both- the traccar app on my phone and the gps watch that the kayaker was wearing but I did not double check the watch start and the traccar app was not checked– I understand this responsibility falls on me.

We left the club at 5:37.07 and finished at 9:52.03. Total time 4:14.56.

Terry, Brian and Duke were all present at the start. About 20+ people were present at the finish.


Click to enlarge.