Sydne Didier - Lake Lyndon B. Johnson

Boulders below Inks Lake Dam to Marble Falls Dam

29.7 km (18.5 miles)

10 hours, 0 minutes on 24 September 2018

Observed and documented by Tiffany McQueen

First swim of Lake LBJ length



  • Name: Sydne Didier
  • Gender: female
  • Age on swim date: 47
  • Nationality: United States
  • Resides: Amherst, Massachusetts

Support Personnel

  • John McQueen - pilot
  • John Urschel - kayaker
  • Aidan Urschel - safety / media / relief kayaker
  • Tiffany McQueen - observer

Escort Vessel: 1997 19’6’’ Cobalt (Kingsland, TX)

Swim Parameters

  • Category: Solo, nonstop, unassisted.
  • Rules: MSF Rules of Marathon Swimming, without exception or modification.
  • Equipment used: Standard swimsuit, silicone swim cap, goggles, sunscreen, Aquaphor.

Route Definition

  • Body of Water: Lake Lyndon B. Johnson (Kingland, Texas)
  • Route Type: one-way
  • Start Location: Boulders approximately 1 mile down-river of Inks Lake Dam (30.721330, -98.396364)
  • Finish Location: Wirtz Dam, Marble Falls (30.555538, -98.338130)
  • Minimum Route Distance: 29.7 km (18.5 miles)


No known previous swims of this route.

Swim Data

  • Start: 24 September 2018, 07:52 (America/Chicago, UTC-5).
  • Finish: 24 September 2018, 17:52
  • Elapsed: 10 hours, 0 minutes, 0 seconds.

Summary of Conditions

Feature Min Max
Water Temp (F) 78 81
Air Temp (F) 71 86
Wind (mph) calm 6

GPS Track

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

Speed Plot

Nutrition: Gatorate and Clif Hydration were used in 1⁄2 hour intervals. 6 bottles were measured and mixed on the morning of the swim. Crew members aboard the support boat were instructed on how to mix additional feeds, should the need arise. A small cooler was kept on the kayak, also containing Chocolate GU packs, and Citrus Clif Bloks. Additional bottles were kept upon the powerboat with boat crew replenishing the kayak cooler when necessary.

Observer Log

Download PDF


by Sydne Didier

For nearly 25 years, I have been swimming in Lake LBJ in Texas. My husband’s family has a home on the water and each time we visit, I head out for hours, exploring the water in the best way I know how.

Actually a reservoir, Lake Lyndon B. Johnson is one of the seven Highland Lakes and stretches from Kingsland to Marble Falls, Texas. With waters from both the Colorado River and the Llano River, it is approximately 21 miles long, from dam to dam.

When the dam is opened in Marble Falls, there can be a tremendous current. But typically, the dam remains closed and the water is constant, at an even level, and infinitely swimmable. In our times there, I have never been in a situation where the lake was anything but consistent.

Before planning this swim, I had never contemplated doing a marathon in the lake. When we visit, each morning I head down to the dock, hop into the water, I swim for a few hours, and then we go about our day - and hopefully eat copious amounts of barbecue!

In the summer of 2018, frustrated by my inability to settle upon another distance swim, and still suffering from post-swim depression after completing my dream swim around Culebra, it was a random dinner conversation with my husband that sparked a lightbulb moment. We had a boat, a place to stay, and a lake for me to swim! The bonus was that no one had ever undertaken a swim of this kind on the lake.

In fact, in all of my years visiting, I had never seen another swimmer in the lake. I’d seen people playing in all ways, but never swimming for the sake of swimming.

It was decided. I would do this.

Just the fact of the lake being there, and swimmable, wasn’t quite enough for me, and I knew that I needed to make it about more than just my swimming.

I have been incredibly impressed with the work of the Texas Civil Rights Project.

An organization of lawyers “boldly serving the movement for equality and justice in and out of the courts. We use our tools of litigation and legal advocacy to protect and advance the civil rights of everyone in Texas and we partner with communities across the state to serve the rising movement for social justice. We undertake our work with a vision of a Texas in which all communities can thrive with dignity, justice and without fear.”

I decided that for the first time, ever, I would do a fundraising swim. This added another level of difficulty for me as I HATE asking people for things, and especially for money. To be clear, ALL monies collected were donated to the organization and NOT ONE PENNY was used for swim-related expenses.

The knowledge that a marathon swim had never been done in the lake, and that I could do it to benefit something I felt strongly about, acted as a perfect motivator. I had to train, I had to swim, and I had to finish this thing.

With the details in the works, we settled upon September as the perfect time to make the attempt. The lake is close to Austin, and in the summer, the temperature of the water, often in the mid to high-80s, and the ever-present boat traffic, make conditions less than idea. By September, kids have returned to school, the boat traffic has lessened, and on a weekday morning, the lake is practically empty but for a few fishing boats.

I have the bonus of having two of my crew members, my husband, John Urschel, and my son, Aidan Urschel, having been through this many times. In planning, however, I knew I needed additional crew and put a call out, seeking a qualified observer in the surrounding area. As luck would have it, the wonderful Tiffany McQueen was less than two hours away from the swim site. The fantastic bonus was getting her AND her exceptional husband, John McQueen.

Both are experienced at this marathon swimming game, with Tiffany both swimming and observing many swims of this type, and John acting as support person extraordinaire. I knew I would be in expert hands with Tiffany as Observer and John as Captain.

I contacted a kayak rental company, rented a boat for the two-day window of the swim, and we headed to Texas.

22 & 23 September 2018

Arriving in Austin on the 22nd of September, we picked up our enormous pick-up truck, a first for me, and set about getting food and supplies for the house.

The lake looked beautiful, the water seemed to be going in the right direction, and standing on the dock at our house made me feel confident that this would go smoothly.

And did I mention that we got to drive a HUGE pick-up? Bonus!

The next day, it was all swim prep as we had determined that Monday would be the ideal day to make the attempt. If things went wrong, or the weather was iffy, that would give us enough time to reset and try again the following day.

We headed to Marble Falls, the town where the swim would end, to pick up our kayak, and meet Tiffany and John for lunch and a pre-swim meeting.

Driving from our house, about at the halfway point of the swim, I started to feel my nerves kick in. This lake was LONG!

This was the first time we had met in person, but there’s something about other swimmers that always feels like home. Immediately, we started talking swims, the two Johns comparing support notes, and Tiffany and I sharing swim thoughts.

We talked through the route for the swim, initially planned as a direct point-to-point from Inks Lake Dam to the Lighthouse at Horseshoe Bay, in Marble Falls.

Although everyone was familiar with the rules of Marathon Swimming, we went over them briefly and I also handed Tiffany the observer sheets, crew contact list, and other information I had printed for her. I also made it clear that Tiffany and John M. would be the final authorities for the swim, with the ability to make whatever call they deemed appropriate given the condition of either the swimmer or the weather.

We discussed where the boat would stay relative to swimmer and kayak, with John staying to my right, my dominant breathing side. We also discussed how radio communication between the kayak and support boat would work, and what would happen in case of emergency.

We headed to the grocery store, buying much more food than anyone could have eaten. (And a special box of Cheez-Its for the beloved observer, because we needed her sharp and on the ball!)

Dropping the food at home, we jumped back into the truck and drove to the expected swim start to see where we’d be able to put in. We’d examined it all on Google Earth and it looked as if we could drive directly to the start, leaving a car there and having the boat come up from the house to meet us.

That was when the first hiccup revealed itself. Due to the nature of the security fences at the Inks Lake Dam, and the lack of road access to the water itself, there was no easy kayak drop point.

We also realized that on the water, rock outcroppings approximately a mile from the dam prohibited the power boat from getting to the desired start, and would require that if we were to start at the dam, John would have to paddle upriver. While we had a back-up plan of using Tiffany’s SUP to get her to a place where she could observe that initial mile, there was no real way to get me there without either being towed or having me swim the mile from the past point our powerboat could access.

In addition, we could not easily assess the swimmability of that portion of the lake as some parts have submerged rocks that make sections impassable.

This was a disappointment. I truly wanted the swim to be from point-to-point, covering the whole lake and offering that sense of completion.

But as swimmers know, sometimes things don’t go according to plan and we must adjust. There is no such thing as total control in an open water swim.

We returned to the house. We had already planned on driving the entire route on the water and figured we would determine just how close we could get to the Inks Lake Dam. That would be our new and improved starting location.

It was getting late and we need to get on the water to have enough time to fully assess the route.

Then, the boat wouldn’t start.

Our family boat, it has always been predictable, well-serviced, and had no issues with reliability - until the day before the swim!

Thankfully, we had an external battery charger to charge the boat battery, and after another hour or so, we were on our way. (I confess that I spent the charging time researching where we could rent a boat before the next day, ready to do whatever needed to happen for the swim to occur.)

Finally, the boat started and we were off.

The lake was beautiful at night, and it was good to explore, evaluating landmarks and familiarizing Tiffany and John M. with the lake.

Near the Inks Lake Dam, there was a certain outcropping of rocks that looked to be the perfect starting place. While it was made abundantly clear that the power boat could not pass through to get to the Dam itself, we could start at the rocks.

With that, the route was settled and it was time for a bit of play.

24 September 2018 - The Big Day!

The next morning, we were up early. I had prepped most of my gear the night before, but I had to check everything a few million times more, confirm that I had at least 4 pairs of goggles, sunblock, gloves for sunblock application, aquaphor for chafing, and all of the other little things I surely couldn’t do without. I also mixed my feeds, and loaded them into the coolers.

While I managed my swim gear, the crew took the coolers, feeds, and kayak to the boat and loaded up. In minutes, we were ready.

(All thumbnail photos, click to enlarge.)

Thankfully, this time, the boat started easily. We had waited for daylight since the lake is quite dark during the night, and that made it easier to load the boat. 
We left the dock, and headed up the lake to the boulders start location. 

 It was a beautiful morning, not hot yet but also not so chilly as to make getting into the water feel unbearable.

The water was perfectly still, especially once we passed under the bridge in Kingsland and headed up the Colorado. As with the trip in the car the day before, the boat ride seemed long. I was going to swim this. Huh. So that was going to happen. 
 We arrived at the rocks, stopping the boat a safe distance away since it was hard to see exactly how shallow the water was, and how high the rocks below the surface actually were.

Despite my initial disappointment about not starting at the dam itself, this now felt like the perfect place to begin. While the crew readied the kayak, and John U. prepped for his long day of paddling, I entered the water and swam to the start.

The rocks were covered with small turtles, seeking the heat the same way I did.

The water was lovely. I am often hesitant about cold water - okay, ALWAYS hesitant about cold water. It felt chilly to start, since the air temperature was still in the low 70s, but I quickly adapted and I knew it would be the right temperature for me throughout the day. (Have I mentioned that there is no ice swimming in my future?)

I arrived at the rocks, waited for my crew to give me the signal, and then, it was time! All timers and GPS devices started, and I began to swim.

As with all of my swims, the first few hours were about adjusting to the event. My goggles were leaking, which led to frustration until I changed them for another pair at the 2-hour mark. I tried to get into my rhythm, reminding myself to focus on the stroke I was swimming, and not think ahead about how long there was to go. 

Familiar with the lake, and the houses that border it, from boating over the years, I found myself playing a game of trying to remember where each house was on the water. Was that big log cabin looking one a few miles up or was it before the ranch one with the big water trampoline? It’s a dangerous game because it means you quite often think you have gone a longer distance than you actually have. What did it mean when I passed the big house with the basketball court on the dock, or the one with the water swings?

I tried to focus on enjoying the scenery on every breathing stroke, and in my mind, said hello to the cows that came to visit the shore.

For once, my feeds were sitting well and I was thankful for that. I’d opted for simple, going with Gatorade, Clif Hydration, Clif Blox, and Clif Shots. While Gatorade may not be a glamorous choice, it seems to be the one thing that my system will tolerate and keep in. (In training, I once again tried CarboPro, Infinit, Tailwind, and any number of other options and am beginning to think that I have a reaction to maltodextrin mixes.)

For this portion of the swim, the water stayed beautifully calm, and while there was no perceptible helping current, I could swim smoothly and easily without feeling like the water and wind were working against me. 

This made it very different from my Culebra swim, where the currents and wind and open ocean conditions made every stroke a challenge. Of course, calm swimming presents a different kind of mental challenge as the physically difficulties can act as a distraction. And since the water was silty, there was nothing to see.

But I plugged away, stroke after stroke.

When it felt difficult, I tried to think about the people I wanted to help, the monies I had raised, and what I was doing this for.

The cloud cover was welcome, as were the moments of sun that poked through. I felt physically comfortable, no aches and pains, no neck discomfort because of sighting. My stroke rate was consistent and I could just swim.

Finally, after about 4 hours, we reached the bridge at the junction of the Colorado River and the Llano River. I’d been under this bridge countless times on a boat, always marveling at the mud nests built under the edge.

Swimming under it felt different, and more exciting. It also represented the moment we would enter the wider part of the river, and when the swim would change a bit.

Suddenly, the water was colder, with bits of frigid temperatures followed by warmth again, over and over as the two bodies of water tried to mix. This was a difficult in a few ways as the cloud cover was more abundant, and I was cold.

I felt myself shiver, and worried that this was going to be the temperature for the rest of the day.

Thankfully, the feeling didn’t last for long, and I felt optimistic as we approached our house, a point I knew to be about halfway through the swim or approximately 9.5 miles completed. 

I was feeling a bit sore, so I had some ibuprofen, mixing up my feeds a bit with a “treat” of a chocolate clif shot. Yum!

I breathe to my right, and could watch the trees and brush pass as I took stroke after stroke. Then, it started to get hard.

As I’ve said many times, there is a point on each swim when it starts to feel miserable. And miles 11 through 14 were my time for that. I was grouchy, I felt the wind pick up, the water moving against me and my kayaker, and I was frustrated by what seemed like a lack of progress. There was not a lot to see, the water was murky, and I was a bit demoralized.

I felt I should have been farther along. And why wasn’t I faster? Right now and, oh, ALWAYS? Who did I think I was to keep undertaking these swims? I’d never be amongst the upper echelon of marathon swimmers. Could I even swim??

How far was I? Wait - I was only at Mile 12?? How was that possible?? Why was I so SLOW?? Why did I ask my crew how far I had gone, and why did they tell me? 

 It was an unexpected kayaker change that buoyed my spirits. While my son, Aidan, has been on the boat for any number of these swims, and did his first real support on the Lake Zurich Marathon swim in 2014, he has never acted as my kayaker before. When John U.’s back and knees needed a break, Aidan took over as kayaker.

There was something truly special about looking over and seeing him in that boat, making sure I was fed and counting my strokes, managing the navigation, and getting me almost all the way to Horseshoe Bay, an area on the lake near the end of the swim. He takes these kind of responsibilities very seriously, and I felt a mixture of pride and gratitude. How lucky was I to have this kind of support and love?

The water was still choppy, and now moving in the wrong direction, but I knew I would finish.

About two hours later, his back and knees feeling better, John U. re-assumed kayak duties. We were nearly in Marble Falls, and I was feeling optimistic, albeit tired.

In the distance, I could see the Lighthouse, our original finish site. The sky was dotted with puffy white clouds, and being the widest part of the lake, it felt like I was swimming in truly open water. The chop had increased but little by little, the swim was nearing its end.

Passing the original end point was difficult. It had been a long day, and the sun was dipping. At the same time, I really liked the idea of finishing at the dam itself since it would offer a nice sense of completion. If I hadn’t been able to start at one dam, at least I could finish at another.

Slowly, the dam got bigger and bigger.

All the while, my trusty crew stayed vigilant. (Have I mentioned how lucky I was to have these incredible people supporting me? I could not have asked for a more reliable, fun, solid, and positive group to do this with me!)

Finally, we were there! 
We’d made it to the Wirtz Dam where I touched a buoy, shouted “Yee Haw!”, or something like that, swam back to the boat, and it was done.

It was a wonderful feeling to get back on that boat having completed the swim, and also knowing that I had raised $4000 for an organization doing truly fantastic work in the area.

And, um, have I mentioned my WONDER CREW? 

We drove back to the house, ready for food and perhaps a beverage, tired but happy the swim had been a success.

And as if the say that the lake agreed, we were greeted with a gorgeous sunset as our reward.


Just over two weeks after my swim, the rains came to Lake LBJ.

The area experienced historic flooding. The lake was closed for weeks and unsafe due to the force of the water, the debris, and the danger of submerged items.

Many of the houses I swam past are now either gone, or so filled with sediment, it will take a great deal of time and money to even attempt repairs.

At our own house, the boat cabana was filled with close to three feet of mud, and it is still under repair. Thankfully, unlike so many others, the family boat was not one of the ones that washed down the river. Images from the flood aftermath show boats collected at the dam in a jumble along with the many docks and boathouses also washed away.

There were some fatalities, and a bridge over the Llano was washed out, separating communities until the bridge can be rebuilt. The water level reached the very bridge I had gone under, and I wonder what happened to those birds whose nests I have long admired.

When I think with gratitude about my time on the lake, I also think about all those who are now suffering through clean-up and reconstruction.

As always, it reminds me of the power of the water, and how lucky we are in those moments when we are permitted to have a perfect day of swimming.