Cathy Delneo - Round Trip Angel Island

Aquatic Park, clockwise around Angel Island, return to Aquatic Park

10 miles (16 km)

6 hours, 10 minutes on 30 August 2013

Observed and documented by Evan Morrison

First woman to complete RT Angel Island



  • Name: Cathy Delneo
  • Age on swim date: 37
  • Nationality: United States
  • Resides: San Francisco, California, USA

Support Personnel

  • Paul Saab - pilot of SERC inflatable Big Red
  • Evan Morrison - crew / documenter

Swim Parameters

Category: Solo, nonstop, unassisted.

Rules: Equivalent to standard MSF Rules for unassisted swims (though MSF Rules did not yet exist in 2013).

Route Definition

Start @ SERC/Dolphin beach in Aquatic Park, exit through Aquatic Park opening, to west Angel Island, clockwise around Angel Island, return to SERC/Dolphin beach via Aquatic Park opening.

  • Route Distance: 10.0 statute miles (16.1 km)
  • Route Type: island loop
  • Start & Finish Location: Beach between South End Rowing Club and Dolphin Club docks, Aquatic Park, San Francisco (37°48’29.3”N 122°25’17.1”W)


Prior to 2013, records of successful Round-Trip Angel Island swims had not been systematically maintained, and existed primarily as brief narrative reports archived in the SERC email listserv. At the time, four people were understood to have done it (unassisted or otherwise): Rick Barthels (1995), Tom Linthicum (2009), Mike Tzortzis (2009), and Hendrik Meerman (2011).

In the weeks leading up to Cathy’s attempt, we talked to a few of our neighbors at the Dolphin Club. Suzanne Heim-Bowen has done a number of remarkable swims in the Bay over the years, and we figured if anyone over there had done it, it would be her. However, we confirmed that she had not.

Cathy is the first woman to complete the swim.

Round Trip Angel Island - list of solo swimmers


0421 slack | 0737 2.4F | 1030 slack | 1245 1.3E


Swim Data

  • Start: August 30, 2013, 04:10am.
  • Finish: August 30, 2013, 10:20am.
  • Elapsed: 6 hours, 10 minutes

Summary of Conditions

Feature Min Max
Water Temp 17C 17C
Air Temp 15C 18C
Wind calm 10 knots

GPS Track

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

Speed Plot

Observer Log

NYC Swim log used, as this was a qualifying swim for the 2014 Manhattan Island Marathon Swim.

Download PDF


Cathy Delneo - Round-Trip Angel Island from MSF on Vimeo.


Station FTPC1 - Fort Point, San Francisco, CA

Wind Speed

Water Temperature

Air Temperature