Small changes, big impacts: Riblet foil helps to 1st place

Small changes, big impacts – Riblet foil helps to 1st place

Between August and September 2021 the competitions of the Trainera Rigatta, once in the Liga San Miguel and once in the Bandera de la Concha, took place in San Sebastián, Spain. About 12 teams consisting of 13 rowers competed in several exciting sub-competitions in order to reach the hoped-for first places. In the end, the team Itasoko Ama Santurtzi from the fishing village of the same name near the metropolis of Bilbao made it twice – BST is very proud to have contributed a small part with a big effect.
© Foto Aitor Arrizabalaga / Eusko Label Liga

From fishing boat to premier league

Santurtzi, now a small suburb of the Basque city of Bilbao, is a former fishing village known for its affinity to water. It is therefore hardly surprising that a rowing club was founded there, which went far this year.
Time and again, the club from Santurtzi has recorded successes since their founding in 1976 – on the one hand as a rowing team itself, on the other hand some members grew beyond the club and became successful in other disciplines.
In 2017, the team made it to the first league in Trainera rowing with their boat – La Sotera. After a first victory in Liga San Miguel in the years since their promotion to the league, this year they actually celebrated two first places – one in the already well-known Liga San Miguel and one in the Bandera de La Concha.
While Liga San Miguel consists of 18 races, some with two days of racing, the Bandera de La Concha has only two races to win in two days. However, a good performance in the Liga San Miguel is crucial for participation in the Bandera La Concha: only the best eight out of a total of twelve teams of the season are allowed to participate in this event and prove their skills.
The determination of the winning team is very simple.

  • On both race days, the individual teams row a previously defined course.
  • Here the time is stopped.
  • The times of both days are finally summed up.
  • The team with the lowest time wins.

While Santurtzi finished second on the first day of the race with a time difference of 1.74 seconds, they beat the winners of the last three years, the Hondarribia club, by a margin of 2.22 seconds on day 2 of the races. So, with a difference of 0.48 seconds, Santurtzi was able to claim a victory in the famous race for the first time in 36 years.

Advantage through Riblets

To improve the performance of the boat, the use of riblets was considered. Similar to other sport boats, La Sotera is stored out of the water and the hull is thoroughly cleaned after each race to avoid possible fouling that would slow down the boat during the race.
In this way, possible micro-textured surfaces are kept clean and can improve performance by up to 5 to 15 seconds, depending on the actual flow conditions between the water and the boat during a race.
BST’s Riblets were therefore applied to the parts of the boat that were continuously underwater – such as the hull. The bow, on the other hand, was not considered. The reason for this was the swell: due to this, during rowing, the bow would temporarily protrude out of the water; the application of Riblet foil to these surfaces would not provide any significant benefit.
In the end, it can be said that the lower frictional resistance, made possible by the application of precisely designed Riblets to the hull, contributed significantly to the victory of the Basque rowing team. A small contribution with a big effect!