Purpose. The objective of this study was to determine the relationships of peak oxygen uptake ( V̇O_2peak), power at V̇O_2peak and power at the anaerobic threshold (AT) with national ranking in a sample of British high performance junior surfers. Methods. Eighteen male surfers (aged 15.4 ± 1.4 years) from the British Junior Surfing team were tested for V̇O_2peak and AT using an adapted kayak ergometer; national ranking was used to indicate performance level. The AT was identified as the point at which V̇E/V̇O₂ started to rise without a concomitant increase in V̇E/V̇CO₂. Spearman’s rank (r_s) and partial correlations (r_p) controlling for age were used to identify the relationships between the physiological variables and national ranking. Results. Mean V̇O_2peak was 3.1 ± 0.5 l · min^-1 (47.7 ± 7.2 ml · kg^-1 · min^-1) and mean AT occurred at 48.1 ± 12.2 W. There were significant correlations between national ranking and power at V̇O_2peak (r_s = -0.549, p = 0.028), power at AT (r_s = -0.646, p = 0.009), and age (r_s = -0.579, p = 0.012). Significant partial correlations were established controlling for age between national ranking and power at V̇O_2peak (r_p = -0.839, p = 0.000) and power at AT (r_p = -0.541, p < 0.046). Conclusions. The power outputs associated with V̇O_2peak and AT were significantly related to surfer ranking in this sample. However, due to the low coefficient of determination associated with the AT/ranking relationship, AT does not discriminate well between the ranking of surfers. These findings support the inclusion of power at V̇O_2peak in assessment batteries for junior competitive surfers.