Betsy Sandberg - Isles of Shoals

Appledore Island to Rye

10.1 km (6.3 miles)

5 hours, 36 minutes on 20 August 2023

Observed and documented by Kim Wesson



  • Name: Betsy Sandberg
  • Gender: female
  • Age on swim date: 54
  • Nationality: United States
  • Resides: Durham, New Hampshire

Support Personnel

  • Harry Wesson - boat pilot
  • Joe Orzel - feeder
  • Gail Pentheny - photographer


Kim Wesson

CPR/AED/First Aid, USMS swimmer. Friend of swimmer.

Escort Vessel

Name Type Port
A Boat Time Seachaser 22’ Dover, NH

Swim Parameters

  • Category: Solo, nonstop, unassisted.
  • Rules: MSF Rules of Marathon Swimming, without exception or modification.
  • Equipment used: Textile swimsuit (Sporti Thin Strap one piece), silicone cap, Aquasphere goggles, Sharkbanz.

Route Definition

  • Body of Water: Bigelow Bight, Atlantic Ocean
  • Route Type: one-way
  • Start Location: Appledore Island (Shoals Marine Lab Dock) (42.987331, -70.617163)
  • Finish Location: Rye Beach Extension, Rye, NH (43.026564, -70.728682)
  • Minimum Route Distance: 10.1 km (6.3 miles) (map)


The Isles of Shoals are a group of small islands and tidal ledges situated approximately 6.5 miles (~10.5 km) off the east coast of the United States, straddling the border of the states of Maine and New Hampshire. Islands and Ledges in Maine: Appledore, Smuttynose, Duck, and Cedar Islands, Islands in NH: Lunging, Star, and White Islands. They have been occupied for more than 400 years, first by fishing communities and more recently as the site of private homes, a large seasonal hotel and a marine research facility.

Significant background research was done by Bob Fernald and Alyssa Langlais to claim her first MSF documented swim from the Isles of Shoals to Wallis Sands Beach in Rye, NH in 2020. She included a table of known swims from 2008-2020.

Most swims started or stopped at the Gosport Harbor area (Bell RW IS) at Star Island. Since this is a working harbor for tourism and boating, recent swims have started from White Island or Appledore Island. There is a protected rocky boat landing on the south eastern side of the White Island. Appledore Island has a boat ramp and a dock belonging to the Shoals Marine Laboratory for which permission must be sought.

On August 20, 2023, a group of 8 solo swimmers and 3 relays started at the Shoals Marine Laboratory dock on Appledore Island and swam to Wallis Sands Beach. The swim was a commemoration of the 50th anniversary of the effort to defeat a proposed supertanker port at the Isles of Shoals with a pipeline to Rye, NH and an oil refinery in Durham, NH. This swim was a fundraiser for the Blue Ocean Society for Marine Conservation, based in Portsmouth, NH. Swimmers raised over $21,000 for the non-profit group. Betsy was the only swimmer to complete an observed swim of this route according to MSF rules. The same day Alyssa Langlais completed a double crossing to the Shoals via her prior route from White Island.

Swim Data

  • Start: 20 August 2023, 08:41:00 (Eastern Daylight, America/New_York, UTC-4).
  • Finish: 20 August 2023, 14:17:15
  • Elapsed: 5 hours, 36 minutes, 15 seconds.

Summary of Conditions

Feature Min Max
Water Temp (F) 60.1 64.4
Air Temp (F) 68.8 82.9
Wind (mph) 4.5 14.1

GPS Track

Trackpoint frequency: 10 minutes. Download raw data (CSV).

Click to expand map.

Speed Plot

Nutrition: Infinit custom mix liquid fuel, every 30 min.

Observer Log

Download PDF

Swimmer Statement

Swimming from the Isles of Shoals to the mainland in Rye, NH is a challenge I envisioned several years ago. In 1973-74 my mother and 2 other women led the opposition to the plan to build the world’s largest supertanker port at the Isles of Shoals with a pipeline to Rye and through several towns to the proposed oil refinery in my hometown of Durham, NH. This proposal was defeated by the combined efforts of citizen groups, a freshman legislator, and the stalwart reporting of Phyllis Bennett at our local newspaper. Later in my childhood, Phyllis’s daughter, Meredith and I swam for the Oyster River Otters swim team in Durham. On the 50^th^ anniversary of the refinery battle and in commemoration of the efforts of our mothers, Meredith and I, along with 9 other teams of swimmers, crossed the ~6.5-mile bight where the oil pipeline would have been laid.

In preparation I trained with my local open water swimming group starting in a pond in March and April and then in the ocean in Rye, NH. This group includes Bob Fernald, who planned and coordinated the swim from the Shoals to Rye. There are several other very accomplished marathon swimmers who also freely share their expertise to help those who are newer to open water swimming. My regular 2-mile swims increased to 4-mile, then 6-mile stints over the course of several months. I faced a range of temperatures and conditions and I felt confident that I would be able to swim the distance and tolerate the temperatures of the Gulf of Maine for this late summer swim.

The main challenge before the swim was that I got COVID 8 days in advance of the swim window. This created a lot of uncertainty and I wondered if it would derail the careful training and planning I had done. I was very fortunate to have mild symptoms and was able to get back in the water after a few days. The main challenge of the swim was having a headwind the entire way, which is something I had faced many times but not for a that distance. This lengthened the time I was in the water over what I anticipated by about 30%. Being in the water longer did not pose a problem at the 61-63 degree temperatures we had. The duration was longer that I had done in training but as I got closer to the finish I was buoyed by the excitement of completing my first marathon swim.


Betsy Sandberg from Gail Pentheny on Vimeo.


WMUR: Beach clean-up, swim in Rye celebrates 50th anniversary of stopping oil refinery on Isles of Shoals