Sarah Roberts - Round-Trip Angel Island

Clockwise loop around Angel Island from Aquatic Park

16.1 km (10.0 miles)

9 hours, 30 minutes on 27 April 2019

Observed and documented by Vanessa Lea



  • Name: Sarah Roberts
  • Gender: female
  • Age on swim date: 35
  • Nationality: United States
  • Resides: Redwood City, CA

Support Personnel

  • Jim Bock - pilot
  • David Roberts - crew chief, kayaker
  • Laura Hovden - kayaker
  • Vanessa Lea - observer

Escort Vessel: South End Rowing Club inflatable Miller Time (a.k.a. “Big Red”)


Swim Parameters

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

Route Definition

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


LongSwimsDB: Round-Trip Angel Island

Swim Data

  • Start: 27 April 2019, 01:38:00 (America/Los_Angeles, UTC-7).
  • Finish: 27 April 2019, 11:08:14
  • Elapsed: 9 hours, 30 minutes, 14 seconds.

Summary of Conditions

Feature Min Max
Water Temp (F) 53 56.5
Air Temp (F) 53 69
Wind (Beaufort) F1 F5

GPS Track

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

Speed Plot


Observer Report

Download PDF

Narrative by Vanessa Lea

April 26th 16:00hrs Sarah and her crew gathered at South End Rowing Club (SERC) to prepare the “Big Red” zodiac and the single kayak for Sarah’s swim. We met in the cook shack to review the MSF standard rules, tides, weather forecast, timing, and the swim plan. Everything looked favorable and after an agreement to all move forward, and agreeing on our roles and responsibilities, we had a quick dinner and were mostly asleep by 20:00hrs. The alarms sounded at 00:15hrs on April 27th and off we marched, from our favorable lodging just two blocks away courtesy of Darlene Bagley, to SERC with supplies and gear.

Sarah was changed and ready on SERC beach at 1:30hrs as planned. But a small crew snafu, involving a foot and most of a leg in the water off the side of the dock instead of into the boat, resulted in a slight delay, and one cold, wet foot and leg for the next 9 hrs and 30 mins. We had agreed just to have 2 kayak shifts, starting with Laura Hovden and then switching to David Roberts halfway through. This proved to be a great decision later as the sea and wind grew quite testy.

Sarah entered the water at the sound of the air horn and a resounding GO, at 1:38hrs on April 27th swimming strongly out of Aquatic Park Cove, with gentle winds, and reasonable calm sea, hoping to meet a slack tide. But as the entire swim proved to us, tide charts are not an exact science, especially in the spring melt season. Sarah was immediately hit with a strong flood moving her quickly East, and we were soon in line with the Jeremiah O’Brien, but with an increasing distance from the shore. A quick change in heading from our Pilot Jim Bock and some steady swimming took Sarah to the west tip of Alcatraz in a reasonably good time. Then it seemed we hit a back eddy, and she flew to the west end of Angel Island. However, now the wind had started to increase, the wave height was gaining maybe 2-3 ft, and we needed to ensure we got around the Angel Island west tip fast.

The sky was foggy but every now and then we could see the half moon over Alcatraz and the city beyond. Quite a sight. Sarah moved quickly into her 54 stroke count average which she is renowned for, a more consistent swimmer there is not! She had started her feeding regime 60 minutes in, and now stopping to eat and drink every 30 minutes, with her happy disposition evident, despite the worsening conditions. Oh yes, and she was very well hydrated it seems, as she reported that she had added quite a lot of water back into the Bay on every feed during her swim!

As we rounded the west end of Angel Island the wind starting gusting over 20mph. It was now at our backs, so it pushed Sarah along well. She didn’t seem to be having any problem with the wave height, it was only affecting her crew, who were cold and wet in the wee hours of the morning!!! We moved into the lee of the island and things dramatically calmed down, as did the flood tide! Hmmm, we need to get around the east end of Angel Island before it changes, else we may get stuck in Racoon Straits. Not a good plan! At this point, it was a great time to shift kayak duty from Laura to David. This was completed reasonably easily given the sea conditions, and not a moment too soon as the wind started increasing quite dramatically. Sarah was still swimming at the same pace and was not being affected by anything, she seemed to be very happy in the ocean and wasn’t the slightest bit cold.

The sky had started to lighten along the back-side of the island and we could see white caps all around, but mostly in front of us! At this point, the zodiac women crew rebelled as they needed a shore pit stop. Leaving Sarah with David her trusty kayaker, our Pilot zoomed us over to an abandoned, broken-down pier, where we quickly alighted, ran onto the beach …and, well you get the gist!! We were immediately back with Sarah, the entire maneuver taking just a few minutes, which was terrific given the layers of clothing being stripped away!

Now we could see the increasing number of vessels surrounding us. All through the swim Pilot Jim maintained contact with Vessel Traffic. They were very aware of our location, as were the numerous ships. We could hear Vessel Traffic announce to ship crews, “Swimmer in the water heading around Angel Island East….”, followed by an incredulous “…please come again…did you say a swimmer…over?”. But they all passed easily, and we didn’t have to change our course, but I bet there were a few pairs of binoculars trained on Sarah!

As we fast approached the eastern tip of Angel Island, we could feel the tide start to turn into an ebb, but we made it around. This was not, however, our main concern. The wind was gusting to over 25mph, one gust was reported at 32mph. The sea was large and alive, waking up to the morning, and Sarah seemed to be surfing on top 4ft swells. The sun had decided to show it’s face to us with blue sky patches and fog scudding over the sky, but very windy still. We took a heading to the eastern tip of Alcatraz, but we were soon to realize that the current had other ideas on our route. As we neared the island, we were being pushed increasingly to the west.

We saw an organized Alcatraz swim drop its swimmers at the eastern tip, and we followed them visually and by radio as they quickly were swept west. Ok so the current was strong, but could we get through?

It was a long hard slog to the island, and we were still pushed west. Sarah was determined to keep heading east but on a quick reconnaissance ride up the back side of Alcatraz, the shoreline being just 100 yards away from our swimmer now, we quickly realized that she would never make it. Sarah went approximately 1 hour “swimming in place” just off the northern shore! She was also now making these pitiful gasps and cries as she realized her 50+ Alcatraz crossings were not going to help her, she was going backward!

After briefing the crew and Sarah as she sheltered in place just by the western tip of Alcatraz for a quick feed, we agreed to route her around the western tip, between the island and Little Alcatraz, then creep up the southern shore which was definitely more protected from the tide based on the island geography. This was a great idea, and Sarah made good time towards the eastern tip, but she was tired, you could tell by the way she was holding her shoulders. Meanwhile, the organized Alcatraz swim was in big trouble, they had been swept down the “river” as we call it, heading for Fort Point, and now a large container ship was heading in under the Golden Gate. The radio waves were alive with broadcasts with disorganized, frantic, fervent warnings about picking up swimmers from the water, 41 in all, and an angry container ship Captain who had to slow their progress into the Bay. This was a bad scenario for everyone. At this point we came to a protected piece of water behind a rock promontory that gave Sarah an opportunity float and feed, to gather her mind and spirit, to watch the baby seal who had decided to play with her, and for us to tell Vessel Traffic that we would wait here until the container ship passes. Great decision, and you could tell by the tone of Vessel Traffic they were happy we stayed away!

We stayed put for 10 mins which gave Sarah all the time she needed to gather herself for the push home. She had done this before, this was the easy bit. The Alcatraz river was running fast, so we took a heading on the new San Francisco Sales Force tower and took to the crossing! Our kayaker David was experiencing difficulties taking the same line as it was now wind over tide. He peeled away and it was now the zodiac duty to take care of Sarah, yeh, like she needed it. She was like a horse returning to the stable! The current was pushing her quickly west, and as we watched the shoreline it became evident that we were going to miss Aquatic Park! This would mean a long slog up the city shoreline as we had to finish where we started. But then as we got nearer and were opposite Coughlan beach….something strange happened. Yet again the tide tables were utterly wrong, and the flood tide came upon us! YES!!!

Sarah started to fly, Coghlan Beach, Gas House, Fort Mason, a quick last feed, and all those familiar swim milestones were flying past us. The sun came out, the wind died down and we were heading now along the Muni pier until ……….Aquatic Park loomed up in front of Sarah. She stopped at the opening and you could tell how happy she was! We were all safe, and she had just swum around Angel Island!!!! We all cheered as she again turned over those arms heading into SERC beach.

The swim ended at 11.08hrs on April 27th with Sarah striding out of the water with that big, familiar smile. The zodiac had docked ahead of her, and we watched as she correctly cleared the water and we declared her victory. Well done Sarah, the 3rd woman to ever complete an around Angel Island swim from SERC!!!


by Sarah Roberts

On Saturday morning after 9h30min, I completed a Round Trip Angel Island swim.

RTAI crosses 2 channels twice (SF-Alcatraz, Alcatraz-Angel Island). So the first stage if this swim is choosing a day where the tidal shift is minimal (not much change from high to low tide) thus the currents flowing through those channels are light. There aren’t many of those days per year and some are better than others. My day was the first opportunity of the year that seemed appropriate, so I figured why not try for it!

The next challenge is weather and water temp. April is tricky. It can be calm and warm. But it can also be windy and cold. Guess which one I got! All week the wind predictions looks great, 2-4mph winds. Basically nothing. But Friday morning, that changed to 20-25mpg winds. Ugh!! While it’s hard on the swimmer, it’s also hard on the support crew. Keeping a kayak close enough to let me follow is difficult and sitting on a zodiac for several hours in high winds is miserable. But when we got to the club at 1am, my crew was ready to give it a shot. So at roughly 1:30 am, I was toes in.

The first leg of the swim went by pretty quickly. The flood tide came early, but I made it to Alcatraz and Angel Island pretty well. My first kayaker Laura never let on, but the wind was howling and she worked incredibly hard to keep the kayak on course. On the north side of Angel Island, we had about 30min of calm water. What a relief! So after 4.5hr, Laura handed over kayaking duties to David. Almost immediately, a big headwind picked up again. But the sun was rising and we got to enjoy a bit of Angel Island before we headed across the channel again to Alcatraz. As I approached Alcatraz the nice flood switched quickly to a ripping ebb, something I knew could happen during the spring runoff season. I was still on the north side of Alcatraz, but also in the “river of doom” (an area where the current splits around the island and is stronger than in the middle of the channel). I swam in place for an hour. But my AMAZING crew did not give up on me. They buzzed about looking for the best way for me to get around. And they did. I swam west with the ebb and snuck around Alcatraz, then swam east to give myself some buffer for when I needed to cross the next channel back to SF. After patiently waiting for a tanker to pass, I began the long slog across the channel to SF. I finally got close and was abeam the SF Yacht Club (Coghlan Beach) but I couldn’t finish there. I had to finish at Aquatic Park (South End) where I started. Luckily, since the ebb was early, so was the flood! And in a bit of slack tide, I made it back to the opening fairly quickly. Putting me roughly at 13.5 miles total (instead of the straightest route of 10.5). After beating me up for hours on end with wind, chop, swells, and changing tides - I was finally on dry land again. The Bay and Mother Nature did not want me to finish this swim, but I won the day!

I quite literally could not have done this swim without my crew. I can’t thank them enough for getting me around the bay safely, putting up with terrible kayaking conditions, for never giving up on me when it got really tough, and for making me finish at the club (it was hard to see Coghlan so close!). You guys are amazing and I’ll forever share this victory with you. Jim Bock for being my trusty knowledgeable Pilot, Vanessa Lea for the task of Observing, and Laura Guptill Hovden and David Roberts for being fabulous kayakers in challenging conditions.

Thank you to everyone who was on the beach. South End (open water) and PCC (pool) are amazing clubs and amazing people and everyone is so supportive. It was a welcome surprise to see so many friendly faces when I stood up at the finish!

After my swim is ratified by MSF, my name should be added to the short list of completed swims. Shout out to the only other ladies to complete this swim so far. Cathy Delneo and Angel More. Thank you for paving the way for the rest of us!

Weather Data

Via NOAA Station FTPC1 - Fort Point, San Francisco, CA

Water Temperature


Air Temperature


Wind Speed

(gust = dotted line)



Click to enlarge.