Is passive drag dependent on the interaction of kayak design and paddler weight in flat-water kayaking?

Abstract

Drag is one of the major factors that influences kayaking performance. To focus on the drag of the kayak’s hull shape and the paddlers’ weight per se, the passive drag (D_p) was measured on a flat-water sprint course for one paddler with added weights. D_p was measured by an electromechanical towing device using a load cell, at incremental and constant velocities from 2.78 to 5.56 m/s. Three kayaks of different sizes and shapes (Nelo® K1 Quattro-M, ML, and L) were used and the paddlers’ body weight was adjusted with weights so the total paddler weight in the kayak was 65, 75, and 85 kg. The mean D_p increased by the power function of D = kvⁿ (mean R² = .990; SD .006). The D_p went from 21.37 ± 1.29 N at 2.78 m/s to 89.32 ± 6.43 N at 5.56 m/s. For the two lighter weighted kayaks (65 and 75 kg), the lowest D_p was observed with different kayak sizes (M, ML, or L) depending on the target velocity. The manufacturers suggest that paddlers should select a kayak size according to their body weight to minimise drag; however, the results of this study suggest that target velocities, and thus competition distance should also be factored into kayak selection.

Keywords:

• Hydrodynamics
• hull
• single-seat kayak

Acknowledgments

The authors extend their gratitude to Élio Henriques for all the support during this project and to the kayak paddlers that were tested during the towing system development and on the final data collection.

Disclosure statement

The authors of the present document have none financial conflict or benefit arising from the application of the research.

Notes

^* Faculty of Sports, CIFI2D, LABIOMEP, University of Porto, Porto, Portugal.

Additional information

Funding

This work was supported by the Portuguese Foundation for Science and Technology [grant number SFRH/BD/69823/2010].