
Product Overview
The Swimrunners Piraya pull buoy is designed and produced by Swimrunners, a Denmark based company that was founded by swimrun athletes. The Swimrunners product line includes a modular race belt system that is compatible with a variety of different add-ons including tow lines of different strengths, zippered pouches for gear and nutrition, and pull buoys that come pre-rigged with attachments for the belt system. This Piraya pull buoy review is for the pre-configured pull buoy ready for integration with the Swimrunners belt system (see image below, belt must be purchased separately). Consumers have the option to order the Piraya pull buoy with or without this pre-configured attachment system.
Disclaimer: Swimrun Labs did not receive any payment from Swimrunners or its competitors to write this product review, and acquired the product through purchase at market value.

- Weight: 140g (4.9 oz)
- Dimensions: 29 cm x 28 cm x 11 cm
- Material: EVA Foam
- Color: Black with white logo
- Purchase Options: with or without belt attachment
- Cost: $35 USD without belt attachment, $42 USD with belt attachment (+$20 USD shipping from Europe)
Initial Impressions
- Fit: there are no fancy contours to the center shaft of the double-pontoon Piraya pull buoy, unlike the ARK Keel. This means the fit is quite versatile among a larger number of people with different inner thigh anatomy and femur lengths, however there is less overall potential for a precise and gapless fit. The contours between the pontoons and the center shaft are not smooth, and this may pose a comfort issue for those with larger thigh girth.
- Sizing: One size. Our tester was 5’4” and 125 pounds.
- Aesthetics: No frills, pretty low profile and sleek when strapped to thigh considering its high volume. Black blends in well with all wetsuits.
- Perceived value to the swimrunner: This pull buoy will be appreciated most by swimrun athletes who are intermediate swimmers and have a lot to gain from the body position assist this buoy provides. Advanced swimmers who have dialed in their body position may find that this buoy is overkill and they can get away with a smaller buoy, or even just calf floats to minimize drag from shoes.
Testing Conditions
We tested this pull buoy in 3 very different training settings in order to vet it for versatility before considering it for our race kit at the 2019 Odyssey Orcas Island Swimrun.
- A bluebird training day with many shorter transitions and zero wind lake swimming. Run terrain: non technical, minimal elevation gain.
- Small craft advisory training day with swells, chop, and 2 long swims >1200 m each. Run terrain: non technical, moderate elevation gain.
- Training day largely on technical trail with lots of vert and quick transitions to shorter swims (much like we would see at Odyssey Swimrun Orcas Island)
NOTE: We tested the version of this buoy that came pre-rigged for integration with the belt system, and used the belt during our tests. We simulated what it would be like to use alternate attach and stow strategies, and this significantly reduced the usability of this buoy, especially on land where it’s large volume and sharper angles made it tricky to keep flush with the body and minimize bounce.
**Spoiler Alert** This buoy and integrated belt system performed so well in testing that I decided to race with it at Odyssey Swimrun Orcas Island: 20 miles of running, 6600 vert, 3 miles of swimming. That’s no small commitment, as this baby was strapped to me for over 6 hours while Brooke and I moved ourselves (literally) over mountains to complete the epic course on Orcas Island. Was it the Piraya pull buoy that gave us the edge we needed for the win? We will never know, but it was a definitive upgrade to my race kit!

Testing Results Breakdown
When the buoy was used with the SWIMRUNNERS belt it was almost completely bounce free and un-detectably integrated into my kit while running on non technical rolling terrain. It performed nearly as well on technical single track with steep climbs and descents, with the exception of the occasional interference with bushes and trees lining narrow sections of trail. I really like to kick my heels up and open my stride down hills, which led to an occasional heel strike to the buoy on steep descents causing a few off balance moments. Bottom line- a smaller pull buoy will always be more comfortable on land, but the Piraya pull buoy performed well considering its size.
AWESOME. The Piraya cut 5 seconds off 100 meter times in our controlled pool trials compared to a standard issue pull buoy. The only buoy we tested that performed better in speed trials was the ARK Keel, which shaved off 6 seconds per 100 meters. Those are pretty compelling numbers, especially when you consider how they add up over a race that includes over 3 miles of swimming. Numbers aside, comfort while in the water was excellent. Multiple testers reported no need to engage any extra muscular energy to keep the buoy in place during swims, and even on longer swims it stayed nestled between our thighs. On top of that, it kept my hips so high I felt like I was swimming downhill! I did not have a single complaint about how the Piraya performed in the water.
Transitions were the only area the Piraya pull buoy came up a bit short. Due to its massive flotation, the buoy itself was always seeking the surface of the water. This is awesome while swimming, but when trying to move from a horizontal body position to vertical in preparation for transitioning out of water the strong upward flotation of the buoy was hard to overcome. My 125 pounds were not enough to force the buoy underwater sufficiently to get my feet down in anything more than about 2 feet of water. Sometimes it would go shooting up to the surface before I was ready, and because it was attached to my thigh my leg went with it. Was any of this a deal breaker? No. But was it awkward? Heck yes. My partner got to hear lots of colorful sound effects while I tried to wrangle the Piraya during transitions. Once out of the water though, re-locating the buoy to the outside of the thigh was quick and relatively hands free as the elastic belt attachment pulled it back into place.
Q: What is a piraya anyway?
A: A large and voracious freshwater fish with many sharp teeth. Well there you have it- seems fitting to have to fight the thing now and again.
With only a handful of training sessions and one long course event, the durability of the Piraya pull buoy has been good. There are some subtle impressions on the foam from contact with rocks during transitions, but nothing that compromises the form or function of the product. The elastic thigh attachment is made from relatively thin stretch cord that could weaken quickly with a season’s use. Without the data of an entire season putting the Piraya through its paces, we can be cautiously optimistic and say durability seems good, with no red flags indicating abnormal wear rates. We can’t give full marks in this category due to the limitations of our testing period, but the elastic thigh attachment seems to be the only component where durability may be an issue.
Overall Summary
- Flotation
- Fit and comfort during swims
- Integration with SWIMRUNNERS belt system
- Value
- Awkward during transition
- Potential durability issue with thigh attachment cord
- Cumbersome on narrow singletrack trails
- High European shipping costs
Still not enough info? Look at our in-depth comparison of the SWIMRUNNERS Piraya pull buoy to the top pull buoys used in swimrun competition.