Sydne Didier - Around Culebra

Culebra Island circumnavigation

30.5 km (18.95 miles)

12 hours, 4 minutes on 29 August 2017

Observed and documented by Michele McCabe

First circumnavigation swim of Isla Culebra



  • Name: Sydne Didier
  • Age on swim date: 46
  • Nationality: United States
  • Resides: Amherst, Massachusetts, USA

Support Plan & Personnel


  • Captain Louis Padron - Boat Captain, The Flash Gordon
  • Michele McCabe - Crew Captain, and primary observer
  • John Urschel - Primary Kayaker, Feeder
  • Larry Guild - Secondary Kayaker, Runner between boat and Primary Kayak
  • Aidan Urschel - Safety and Lifeguard

Safety Plan

John Urschel, in single kayak, was primary kayaker for swimmer, with Larry Guild, in second kayak, to assist as needed.

Power boat, captained by Louis Padron, accompanied swimmer and kayaks for the entirety of the day, with Observer/Documentarian, Michele McCabe aboard that boat. Also on that boat was Aidan Urschel, lifeguard, junior firefighter, and trained in Wilderness First Aid.

John Urschel had a Spot Tracker on the kayak, in addition to Garmin 920 on his wrist and phone with GPS tracking in a dry bag on the kayak. He communicated with the power boat via marine radio, and/or voice.

All crew members were instructed on swim protocols and procedures.

Captain Padron communicated with those on shore, including EMT acting on standby should swimmer and/or crew members require medical attention.

I also attempted to contact the Culebra Municipal Government to inform them of plans, but despite reaching out to them on several occasions, was unsuccessful.

Feed Plan

1st Endurance Electrolyte Fuel System (EFS) was used in ½ hour intervals. 7 bottles were measured and mixed on the morning of the swim, and crew members aboard the Flash Gordon were instructed on how to mix additional feeds, should the need arise.

A small cooler was kept on Kayak #1, also containing Chocolate GU packs, and Citrus Clifbloks. Additional bottles were kept upon the powerboat and Kayak #2 replenished the supply on Kayak #1 as necessary.

When it was time to feed, Feeder would shake bottle above the boat, or use whistle to notify swimmer. Feeder used paracord with a carabiner to throw bottle to swimmer, who treaded water while drinking, careful not to touch the boat or kayaker, dropped the bottle, and Feeder then pulled bottled back to kayak when feed was complete. Gu packets were also given using carabiner.

All additional food and liquids for swimmer were kept in cooler on the powerboat, and crew had a separate cooler for food and drinks.

Swim Parameters

Category: Solo, nonstop, unassisted.

Rules: MSF Rules of Marathon Swimming, without exception or modification.

Route Definition

Counter-clockwise circumnavigation of Culebra, Puerto Rico. Start and finish at Mosquito Bay Beach (map).

  • Route Distance: 30.5 km (18.95 miles)
  • Route Type: circumnavigation


No known previous swims of this route.

Swim Data

  • Start: 29 August 2017, 05:50 (Atlantic Standard Time)
  • Finish: 29 August 2017, 17:54
  • Elapsed: 12 hours, 4 minutes

Summary of Conditions

Feature Min Max
Water Temp 85F 87F
Air Temp 77F 90F
Wind calm 12 mph

GPS Track

Trackpoint frequency: 15 minutes. Download raw data (CSV).


  • Raw data from Garmin 920 watch - GPX, TCX
  • Reduced frequency (5 minutes) - CSV

Speed Plot

Observer Log

Download PDF


I was lucky enough to first visit Culebra in September of 2013.

Located off of the coast of mainland Puerto Rico, Culebra is a small island, less well-known than Vieques, and much less developed. Like Vieques, Culebra was used for U.S. military testing, and the abundance of unexploded ordnances has meant that the island is not safe for large-scale development. As a result, the natural environment has been preserved in ways that mean sea life abounds.

I was instantly smitten, and the seed was planted for a circumnavigation.

Since that first visit in 2013, I have returned twice for scouting trips, both times exploring more of the island, swimming at every beach, and with each visit, falling more in love with the island and more committed to this swim.

In June of 2017, I returned for my third visit, this time arranging to meet with island resident Captain Louis Padron would provide support during the circumnavigation, captaining his boat, the Flash Gordon.

On the June trip, Captain Padron and I discussed the execution of the swim, and he offered detailed information the currents and particular challenges presented at various points. Two support crew members, Observers Michele McCabe and Aidan Urschel, were also present and our team was able to strategize and discuss our swim plan.

At that time, we determined that the best direction would be for the swim to begin in the Mosquito Bay area, on the South East end of the island, heading slightly east, then turning North toward Culebrita. The route would then take us between Culebrita, a small island off the shore, and Culebra. Passing Culebrita and heading to the left of Botella Cay and Cayo Norte, two smaller islands off of the shore, Captain Padron indicated that this would be one of the toughest part of the swim as the current pulls left and would require that I swing out into more open water.

Passing Cayo Norte, and passing Brava beach, now on the true Northern coast of the island, Captain Padron indicated that this was open ocean and would also be choppy and challenging. From Resaca Beach and then Flamenco, Captain Padron noted that opposing currents at the Northwest tip of the island would be my biggest challenge. This area is sometimes known as Whirlpool Point, and Captain Padron was clear that it was sometimes impassable even by boat. This would be the trickiest part of the swim, and the area most likely to make or break the attempt.

Having established all we could on the island, we returned to Massachusetts and planned our next trip – THE ONE!

Due to the combination of weather factors and mundane real-life constraints like kids needing to be in school, we decided that the week before Labor Day would be the best time to return to the island and make the attempt.

At home, I prepared binders and/or folders for each member of the team. These included a print-out of the MSF Swim Rules, a Standard Equipment List, Observer log/Documentation Requirements, the Observer Cover Sheet, and several copies of the Standard Observer Log.

Before we knew it, it was time to return to Culebra for the big day! In the weeks before, we checked the weather, knowing that it was also hurricane season and wanting to be sure that conditions would be right, but also that swimmer and crew would be safe throughout.

Thankfully, our chosen week looked good, and on the 27th of August, we flew to Culebra. When we arrived on the island, we talked with Captain Padron, and consulted with other locals (friends at Culebra Divers, the local dive shop in town, and others familiar with island weather patterns) regarding the weather for the week. Based on the forecast, and possibility of wind, rain, thunder and lightning, it was decided that Tuesday, the 29th, was our best choice, and we began our on-island preparations.

We also determined that should something happen, making the attempt earlier in the week would leave time for us to have a “rain date.”

Monday, 28th August - Pre-Swim Day / Team Meeting

The morning of the day before the swim was about acclimating to the water, with a short ½ hour swim to loosen up.

John Urschel, kayak support, tested both the kayak and the Spot trackr we would be utilizing for the swim itself.

At midday, all members of the crew met at our support boat, Flash Gordon.

In attendance were all members of the Support Team.

  • Captain Louis Padron - Captain of the Flash Gordon
  • John Urschel - Primary Kayaker, Feeder, holder of GPS Track.
  • Michele McCabe – Observer, documentarian
  • Larry Guild – Secondary Kayaker, and backup observer
  • Aidan Urschel – Lifeguard, safety officer, backup observer
  • James and Grace Arcoleo - Cheerleaders! Feed mixers.

At the meeting, I read aloud the rules of Marathon swimming, with a careful emphasis on the fact that I was not to touch or make intentional contact with any vessel, object, or support personnel, and that at the finish, no crew member should have contact with me until I had cleared the water and was fully on land.

I also discussed how important it was to me that in terms of the MSF rules, they feel able to be fully impartial members of this team and that they be comfortable being honest if they felt a violation of the rules had been committed.

John Urschel, primary kayaker, has been my support person for the majority of my marathon swims and understands the rules, as well as my determination to stick with them. Michele McCabe, who would act as observer/documentarian, was a competitive collegiate swimmer. Larry Guild, has competed in a variety of sports, including cycling and kayaking. All crew members agreed that they felt fully able to be vigilant about my adherence to the Marathon Swim Rules.

We detailed the roles of each member of the crew, and their responsibilities relative to the swimmer. I described my feed plan, with the bulk of the feeds to be carried on the primary support kayak. Feeds would consist of First Endurance EFS, at ½ hour intervals. Feed bottles would be thrown to me, attached to a carabiner tied to paracord, so that the kayaker could retrieve them easily and I could continue swimming. Additional feeds of ClifBlox and Chocolate ClifShots would be used as necessary, and the support kayak was also to carry a supply of water.

At the meeting, we discussed how the power boat would be outfitted, and where the boat would stay relative to swimmer and kayaks. My preference was to have all vessels to my right, my dominant breathing side, with the kayaks next to me, and the powerboat next to them. Having been my support kayaker for many swims, John also described a bit of what he has observed of my swim patterns - my tendency to pull to the left, where I prefer my kayak support to be for navigational purposes, etc.

We discussed the preferred method for radio communications between the kayakers and the support boat, and went over our weather contingency plans, detailing what would happen in case of thunder and/or lightning. We also discussed drop points around the island (Flamenco Beach, Tamarindo Beach, and Datiles Beach) should a crew member need to exit the water. A friend would be an on-call team member, based on land and available to pick up any crew member who left the boat. Given the size of the island, it was unnecessary to have anyone stationed at each of those points as a single person could travel easily between them, should the need arise.

Team members to remain aboard the Flash Gordon were instructed on how to refill and mix feed bottles when the supply of bottles on the primary kayak was depleted. It was also decided that Kayak #2 would act as a “runner,” bringing feeds back and forth so that Kayak #1 could stay with me at all times. Due to the nature of the reefs surrounding the island, it was clear that sometimes, the power boat would have to take to deeper water than we would be able to swim and kayak through, but that all boats would stay as close to me as possible, while not providing opportunities for draft or assistance.

In addition, I provided the members of my team with a full print-out of the documentation from Jeff Miller’s MSF Documented Circumnavigation of St. John as a model for our own documentation. (I had also emailed all of this information several weeks prior, with the expectation that crew members would familiarize themselves with it and be able to ask questions at our meeting.)

I also described things that they might hear or see as support crew since jellyfish stings were almost guaranteed, as were the inevitable emotional low points that can occur in any event of this type. I assured all crew members that the range of emotions was normal, and that they should not be alarmed as they witnessed me working my way through all of the stages of grief. We also decided that due to the high temperatures of both the air and water, dehydration was a risk, and observer notes would include whether or I not I was able to consume enough liquid to be able to urinate.

Finally, I reiterated that Captain Padron was the final authority for the swim, and that should he decide that conditions were dangerous or that the swim needed to be called for any reason, this was to be understood by all members of the team.

At that time, having evaluated the weather, we determined that we wanted to start just slightly before sunrise, giving me the best chance to complete the swim while it was light out and taking advantage of calmer water in the earlier part of the day.

Tuesday, 29th August 2017 - Swim Day

Crew members began preparation at 4:00 am. I mixed 7 feed bottles while other crew members filled coolers, one with liquids and extra feed supplies for me, and one with food and drink for the crew. I put sunblock on, Solar Sense Zinc.

Captain Padron arrived at Mosquito Bay, aboard the Flash Gordon, at 5:00 am and Larry Guild and John Urschel went down to assist with loading the boat. I left the house at 5:20, walking down the hill toward to beach, remembering the very first time I had taken this walk and entered this water. It felt unreal that the time had finally come for me to make the attempt.

Kayaks had been transported down to the beach the day before, and we loaded the kayak top cooler, an extra pdf, and other supplies onto Kayak #1, to be piloted by John Urschel.

John wore a Spot Tracker on his PFD, utilizing the Trackr RS system for documenting the swim. Backup GPS included a Garmin 920, which he wore on his wrist, and a phone in a dry bag, set to a tracking app. The crew on the Flash Gordon also had two backup GPS devices, and all 5 were to be turned on at the same time, when the signal was given and I entered the water to begin the swim.

Captain Padron and I hugged, and he got on the boat. It was time.

With the boats loaded, the support crew pulled the anchor on the Flash Gordon, and the kayaks entered the water, waiting for me.

I entered the water at 5:50, and all GPS devices were started. This was really happening! After years of thinking about it, I was going to be able to live this dream.

The night before, I had been incredibly nervous, but as soon as entered the water, almost instantly, my nerves were gone. As happens on all of my swims, once I touch the water, it’s as if my mind says “Oh, right, you DO know how to swim! Excellent! Let’s do it.” Perhaps this is the legacy of being an adult onset swimmer, without the benefit of a childhood history of team swimming. Each new swim requires that I remember the process, I remember the joy I feel in the water, and I remind myself of all it gives to me.

I had chosen to wear tinted goggles ( the Aqua Sphere Vista) since I knew the sun would be up soon, so my visibility was limited at the start. It was still relatively dark, but I had spent enough time in this water that it felt familiar. Within 500 yards of shore, I was delighted to see 3 turtles below me, and in some part, it felt like they were sending me on my way.

The first part of any long swim is a complicated time. You know that there is so much to go, and yet to think about that whole is self-defeating. Instead, I spent my time focused on each stroke, one after another, establishing my groove for the day and a stroke count of approximately 67 strokes per minute. My speed was approximately 1:20 to 1:30 per 100 meters, and I felt strong.

Leaving Mosquito Bay, I turned the corner toward Playa Larga. These were still familiar waters, as each time I have visited Culebra, it is where the bulk of my swimming happens. I recognized patches of coral, knew where it would get shallow, and since I felt comfortable with the underwater landscape, focused on my form.

The water was calm and in an area where there had often been wind blowing against me on other swims, it felt unusually easy.

Before I knew it, it was time for my first feed,

The day was gorgeous, with none of the distant rain clouds I had feared, and soon, approaching Culebrita Island, I began to feel a helping current. The sun was truly coming up, and I passed Zoni Beach, moving toward Cayo Norte, an island with a personal history for Captain Padron, whose grandfather lived there for many years.

Passing Cayo Norte island felt long, as if the island was stretching and growing as I swam, but the team assured me that I was keeping a good pace, and was right on track. Feedings felt good, and unlike my swim in Italy the Summer before, I was not having any issues with digestion. The EFS was a better solution for me than CarboPro, and I never felt hungry or lacking nutritionally.

At Cayo Norte, the turtles abounded, so many that I stopped announcing it to my crew because it was taking too long to stop each time. I saw one turtle with a cracked shell, missing a large chunk out of the right back end, something I had never seen before.

I also saw my first shark of the swim, a large Nurse shark, completely disinterested in me. Sharks and Rays and Turtles! It was as if all of the things I loved about the island were spurring me along!

I was also beginning to encounter larger and larger patches of Sargassum, a brown seaweed that was sharp and prickly to the touch, and which felt like it scraped my body each time I grazed it. It also held tons of sea lice, and parts of my swims became a bit of a dodge and weave, with John and Larry pointing out large patches in advance, trying to guide me around them as much as possible. Often, they were impossible to avoid and I tried to dive beneath, coming up for air and then diving again until through a patch. Each time I hit a patch, it felt as if I was swimming through tacks, razor sharp but thankfully, not long lasting.

The sea lice were no worse than I am used to, but in combination with the sargassum, it was frustrating to feel nearly constant pinpricks across my body. Listening to my occasional yelp, John joked that the ocean was throwing everything at me in an attempt to counter my hubris. Who did I think I was to assume I could swim around this island??

We approached Playa Brava around 9:21, and while the chop was strong, I still felt confident. And Happy!

We passed Resaca Beach, and before I knew it, Larry announced “Look to your left. That’s Flamenco!” The most famous beach on the island, renowned for its white sand and currently, for the unexploded munitions recently found there, to me it marked the halfway point of the swim. I felt optimistic and excited, and surprised that 10.5 miles had gone by already.

Then, everything changed.

The swim from Flamenco across to the point where I would turn left was another long stretch. Based on what I had been told by island locals, the toughest part of the swim was to come, and the water was feeling rougher and choppier. I was still feeling strong, but apprehensive about what was to come.

I approached the Northernmost tip of the island, a place known as both “Land’s End” and “Whirlpool Point.”

Due to rocks we had not been able to see on our maps, Captain Louis and the crew decided that I would have to swing wide, and rather than cutting between two smaller land masses, I would have to go around, subjecting myself to more intense cross currents, chop and the incessant wind.

Rounding the point, I felt myself stop. While I was stroking as hard as I possibly could, I felt myself going nowhere. My pace per 100 meters dropped from approximately 1:22 per hundred to approximately 3:42 per hundred.

The headwind was strong, and the chop was coming at me, the currents feeling like they were coming from all directions at once. It felt as if I was completely stuck, unable to move forward in any way. I swam and swam and swam, and with each stroke, felt as if I was moving backwards.

My next feed was an unhappy one.

“You’re not making progress,” John said, and I admit, I snapped at him. “You need to find another way to say that! Because that is not helpful.”

In truth, he was merely trying to be accurate, but I was frustrated, and honestly, worried. My speed had dropped considerably, and I could see myself getting pushed backwards. I kept pushing.

Miles 11 through approximately 13 were my toughest mentally. Having felt so good on the first half of the swim, it was a disappointment to realize that the second half was going to be challenging throughout. We had rounded the point, yes, but the relief I had longed for upon doing so was not to be had. The chop continued. The wind picked up.

Plodding along, we headed toward Carlos Rosario Beach, me still only able to maintain a pace between 1:30 and 2:30 per 100, depending upon how big the waves were at any given moment.

I noticed John laughing. “What’s up?” I asked. “Larry’s kayak filled with water. They’re on the boat trying to empty it.” I looked over to the Flash Gordon and Captain Padron, Larry, Aidan, and James held the kayak in the air, upside down, as they tried to dump water out of it.

For some reason, this bit of comic relief was the boost both John and I needed. I resigned myself to the fact that the rest of the swim was going to be difficult, admitted to myself that I missed the relative ease of the earlier part of the day, and kept going. I also let go of any 9 hour time goals, since that was not going to happen in the conditions I was facing.

Soon, Larry was back, the kayak emptied. And I made my way past Carlos Rosario Beach.

Now that I knew how the rest of the day was going to be, I tried to enjoy the wildlife again, and seeing a giant spotted ray and more turtles perked me up as we made our way to Tamarindo Beach, approximately 15.46 miles into the swim day.

The water currents and wind continued to be unpredictable, with my pace varying from 1:15 per 100 yards up to 3:00, largely depending upon how much I was being buffeted by the wind.

We passed the Channel in downtown Culebra, a rather open section of the swim where the wind was intense. While I didn’t see them, I learned later that there were people gathered on the dock to watch me pass, some of them using SUPs to come out and cheer me on. (Throughout the swim, Captain Padron had been updating Culebra social media, and later, it was lovely to read about people had spotted me at various points throughout the day, following my progress as I went.)

Heading to Punto Soldado was tricky. The wind was still strong, and seemed to be getting stronger, and as happens in every swim, it seemed someone kept pulling the Point out of my reach. Stroke after stroke, I plodded along.

I worried about the crew. Were they bored? Were they getting sunburned? Did they have enough snacks on the boat? How could I ever express my gratitude for what they were doing?

Finally, we reached Punto Soldado, which, in my mind, was almost the end.

That’s the tricky thing about any swim. The end is not always the end, and in reality, I had longer than I would have liked left to go.

Sadly, however, I soon had the realization that despite what my head wanted, the swim had quite a ways left, and the currents would become even more demanding of my strength. It’s quite amazing how clear the map can be in your head before you swim, and how easy it is to misremember when you are actually swimming.

I reminded myself not to let my mind get ahead of my body, and just to swim each stroke.

With fatigue, my tendency to pull left increased and I swam too close to where the waves were crashing, hitting the rocks that littered the shore in the area before the opening for Ensenada Honda, and the final area I would have to cross before entering Mosquito Bay.

No matter how hard I tried to pull right, the waves pushed me toward the rocks until eventually, Larry instructed me to head straight out, perpendicular to the shore. I was tired, I had been bitten on the nose by an unknown small fish, and it was hard to knowingly swim out directly into the oncoming waves again.

This is why we have crews. In the water, we THINK we know best, but really, my crew was right, and once I took to deeper water, the waves were less of an issue, I could turn parallel to shore again, and I started to make more forward progress.

At this point, nearly finished, the Flash Gordon became ensnared in the Sargassum seaweed we had so carefully avoided during the majority of the swim. With the engine on the point of failure, and with less than a mile to go, the boat went ahead to the beach at Mosquito Bay, with John and Larry staying at my side.

I passed a buoy I knew well from training swims, and it was the first moment I genuinely felt that the swim was almost finished.

Eager to get there, I pulled harder, stroking with sore arms but enthusiasm, until I reached the beach, my crew directing me to the spot on the beach free from the sea urchins that litter most of the shore.

Friends had made an arch for me to finish through and I walked out of the water and ran across the beach, my legs surprisingly steady. I sprinted through the arch, half laughing, half crying.

It was done. After years in the dreaming and planning, it had happened.


Less than a week after my swim, Puerto Rico was largely missed by Hurricane Irma. Sadly, little more than a week after that, it was devastated by Hurricane Maria, as was my beautiful island.

Culebra suffered less damage that was feared, but at the time I write this, electricity is only available via FEMA generators, and the water supply is an issue as well. Things are slowly getting back to “normal,” but it’s clear that the island will be living with a new normal for quite some time to come. Due to the fact that economy is tourism based, people are struggling, and because the island and its people have been so incredibly warm and welcoming to me, I have spent time trying to repay the generosity of spirit I received from this wonderful place. It is truly a special spot in the world, and I am eager to return as soon as I can.

If this narrative has inspired you to think of visiting Culebra, please do not hesitate to reach out for suggestions. The island needs us, and has so very much to offer.