Swimrun Pull Buoys — a Brief History

2006–2009: Boys without Buoys

The first public swimrun competition was ÖTILLÖ in 2006. In the beginning, not a lot of people actually used a pull buoy for swimrun. Most swam without any flotation besides their wetsuit. While the main reason was probably that they didn’t even think of the idea of using a pull buoy, another reason could have been that many athletes swam using long fins, which do not play well together with a flotation device between the legs. Also, some used other types of flotation, such as body boards or kick boards. There was even a case of air mattresses in the shape of Nokia mobile phones before a restriction on size was imposed.

A factor that has to be taken into account is the fact that during the first seven or so years, swimrun specific wetsuits didn’t exist. The typical early ÖTILLÖ athlete’s wetsuit was designed for open water swimming, with more flotation than today’s swimrun specific wetsuits. However, a good pull buoy has unrivaled buoyancy and hence today almost every athlete will use one.

Nils Svensson and Andreas Lagerström at ÖTILLÖ 2008. No pull buoy but both with backpacks, something you don’t see nowadays. Photo: capture from ÖTILLÖ YouTube.

2009: Pool Swimmer Influence

The original pull buoy was developed as a training tool for competitive pool swimming. Already readily available, the first actual pull buoys used in swimrun were these swim-training tools, which come in a few different shapes from traditional figure 8 profile to flat boards. Pull buoys saw a gradual adoption during 2009‒2011 at ÖTILLÖ. Ångaloppet – now a popular event in Sweden – held their inaugural race in 2011 but athletes there didn’t use pull buoys until the 2013 edition, judging from pictures from the race.

A standard swim-training pull buoy.

Do It Yourself

The ÖTILLÖ race was – and perhaps still is – the main venue for gear innovation. Around 2011 some athletes came up with the idea of constructing their own flotation devices from pipe insulation and straps as more focus was put on cutting the legs off the wetsuits and going light to make running easier. Both swimmer pull buoys and DIY equivalents were pierced with an elastic cord or two which loops around the waist or one of the upper legs.

Paul Krochack and Björn Englund winning ÖTILLÖ 2015 with pipe insulation. Photo: Jakob Edholm / ÖTILLÖ.

Around 2014‒2017 some people also started experimenting with putting foam materials such as pieces of camping pads or pipe insulation in high socks or calve compression wear. The idea was to provide flotation not just around the hip area but also on the lower legs. Leg flotation seems to have faded into obscurity during the last years and is no longer widely used.

The author back in 2017 when leg flotation was still a thing. Photo: Tero Koski / Folkhälsan Swimrun.

The Yellow Era

Alex Flores and Fredrik Axegård at ÖTILLÖ WC 2016 with the classic yellow air-tank pull buoy. Photo: Andreas Ribbefjord.

One other popular early do-it-yourself pull buoy was the yellow plastic air tanks, which were a rebuild of a children’s flotation device. The origin of this construction is from the (Swedish) elite swimming society where this DIY build has been used in training for years prior. This construction has since been mass produced as swimrun pull buoys.

Hobbyist swimrun gear developer Patric Tengblad took the concept further, cutting and melting together these to make extended versions with more lift. Worth mentioning, the current ÖTILLÖ World Championship course record in the men’s category was set with a Tengblad creation.

The original “simdyna” (sv).
Yellow air-tank pull buoy, originating from Swedish elite swim practice.
Patric Tengblad’s tallest version — 37 cm.

Plastic Bottles

The air-tank pull buoys are popular still today and the newly released Ark Pontoon is quite similar to the original DIY elite swimmer training tool. Another early DIY was made out of two plastic bottles, made famous by WC 2015 mixed gold medalists Marika Wagner and Staffan Björklund. Maja Tesch also had such a pull buoy winning the women’s category the same year, together with Annika Ericsson.

Marika Wagner and Staffan Björklund winning ÖTILLÖ 2015 with plastic bottles. Photo: Jakob Edholm / ÖTILLÖ.

Mass Production

As the years progressed, gear manufacturers such as Swimrunners, Orca, Colting, Head and Ark developed swimrun specific pull buoys along with other gear such as paddles and suits. Specialized swimrun flotation generally provides more flotation than the original swimmer training tools. Also, while dry-land weight was not an issue swimming in the pool, this is also an area of innovation with the use of different EVA-like materials.

Ark Keel (pictured) and Swimrunners Piraya were some of the more popular 2019 state of the art of mass-production swimrun pull buoys.


The last few years some athletes have put two regular swimrun pull buoys together with epoxy glue, making a longer version of the standard issue. The Huub Big Buoy standard-issue has a shape which allures to coupling with one side flat and one sloping. The double Huub (picture below) was popularized by current world champions Pontus Lindberg and George Bjälkemo.

Pontus Lindberg with his trademark double Huub on his way to win the ÖTILLÖ WC 2019 together with George Bjälkemo of Team ATG Sport. Notice the streamlining. Photo: Jakob Edholm / ÖTILLÖ.
Double Huub Big Buoy epoxied by the author — 34 cm, which is no longer legal. The surface side trimmed down, since foam above water does not contribute to buoyancy.

Ark Keel has seen a lot of doubling since its release. It appears as if Daniel Hansson and Kristin Larsson were extending the prototypes even before the release. When Peter Aronsson and Stefano Prestinoni came first out of the water on the first ~ 1 650 m swim of the ÖTILLÖ 2019 World Championship it was with double Keels on their hips, which just proves that even the best swimmers will benefit from more buoyancy.

Alex Flores and Fredrik Axegård again in 2019, with a double Ark Keels at the last grueling islets of the ÖTILLÖ WC 2019 representing their sponsor Ark, taking second place. Photo: Jakob Edholm / ÖTILLÖ.

Thomas Schreven, 2019 ÖTILLÖ WC mixed runner-up together with Jasmina Glad-Schreven, has experimented quite a lot with combining different types of pull buoys to make a larger one. Like many others, Thomas told us that he timed his swims with different buoy version to see which one is faster. There are many aspects contributing to speed: buoyancy, friction, form/drag etc. Thomas also highlights the importance of a good fit in his blog.

Thomas Schreven with a Swimrunners Piraya and Huub Big Buoy merge at the ÖTILLÖ WC 2019. Photo: Jakob Edholm / ÖTILLÖ.

Recent Regulation

Through the years the ÖTILLÖ rules regarding flotation and other gear have largely been adopted by other race organizers. To allow for innovation, the rules have – and still are – quite allowing. For a very long time the restriction on the size of the flotation devices used was 100 x 60 cm, notably only defined in two dimensions.

Perhaps as a reaction to all the double constructions, from August 2019, the new ÖTILLÖ rules were set to 40 x 30 x 15 cm. This was revised to 32 x 30 x 15 cm only two months later and those are still the maximum dimensions allowed at the time of writing. The length of fins was regulated by ÖTILLÖ already back in 2017 limiting that path and steering athletes towards exploring the pull buoy instead.

The future without a doubt has more developments in store in the field of swimrun pull buoys and other gear. To stay up to date with the latest trends, keep an eye on the front of the field where athletes are especially keen to find whatever edge they can on their opponents.

Author: Andreas Ribbefjord
Contributing author: Tomas Granberg