The energetic, macrotidal shelf off South West England was used to investigate the influence of different tide and wave conditions and their interactions on regional sand transport patterns using a coupled hydrodynamic, wave, and sediment transport model. Residual currents and sediment transport patterns are important for the transport and distribution of littoral and shelf‐sea sediments, morphological evolution of the coastal and inner continental shelf zones, and coastal planning. Waves heavily influence sand transport across this macrotidal environment. Median (50% exceedance) waves enhance transport in the tidal direction. Extreme (1% exceedance) waves can reverse the dominant transport path, shift the dominant transport phase from flood to ebb, and activate sand transport below 120‐m depth. Wave‐tide interactions (encompassing radiation stresses, Stoke's drift, enhanced bottom‐friction and bed shear stress, refraction, current‐induced Doppler shift, and wave blocking) significantly and nonlinearly enhance sand transport, determined by differencing transport between coupled, wave‐only, and tide‐only simulations. A new continental shelf classification scheme is presented based on sand transport magnitude due to wave‐forcing, tide‐forcing, and nonlinear wave‐tide interactions. Classification changes between different wave/tide conditions have implications for sand transport direction and distribution across the shelf. Nonlinear interactions dominate sand transport during extreme waves at springs across most of this macrotidal shelf. At neaps, nonlinear interactions drive a significant proportion of sand transport under median and extreme waves despite negligible tide‐induced transport. This emphasizes the critical need to consider wave‐tide interactions when considering sand transport in energetic environments globally, where previously tides alone or uncoupled waves have been considered.

Headland bypassing is the transport of sediment around rocky headlands by wave and tidal action, associated with high-energy conditions and embayment circulation (e.g., mega-rips). Bypassing may be a key component in the sediment budget of many coastal cells, the quantification of which is required to predict the coastal response to extreme events and future coastal change. Waves, currents, and water levels were measured off the headland of a sandy, exposed, and macrotidal beach in 18-m and 26-m depths for 2 months. The observations were used to validate a Delft3D morphodynamic model, which was subsequently run for a wide range of scenarios. Three modes of bypassing were determined: (i) tidally-dominated control during low–moderate wave conditions [flux O (0–10² m³ day⁻¹)]; (ii) combined tidal- and embayment circulation controls during moderate–high waves [O (10³ m³ day⁻¹)]; and (iii) multi-embayment circulation control during extreme waves [O (10⁴ m³ day⁻¹)]. A site-specific bypass parameter is introduced, which accurately (R² = 0.95) matches the modelled bypass rates. A 5-year hindcast predicts bypassing is an order of magnitude less than observed cross-shore fluxes during extreme events, suggesting that bypassing at this site is insignificant at annual timescales. This work serves a starting point to generalise the prediction of headland bypassing.

Improved understanding of how our coasts will evolve over a range of time scales (years‐decades) is critical for effective and sustainable management of coastal infrastructure. A robust knowledge of the spatial, directional and temporal variability of the inshore wave climate is required to predict future coastal evolution and hence vulnerability. However, the variability of the inshore directional wave climate has received little attention, and an improved understanding could drive development of skillful seasonal or decadal forecasts of coastal response. We examine inshore wave climate at 63 locations throughout the United Kingdom and Ireland (1980–2017) and show that 73% are directionally bimodal. We find that winter‐averaged expressions of six leading atmospheric indices are strongly correlated (r = 0.60–0.87) with both total and directional winter wave power (peak spectral wave direction) at all studied sites. Regional inshore wave climate classification through hierarchical cluster analysis and stepwise multi‐linear regression of directional wave correlations with atmospheric indices defined four spatially coherent regions. We show that combinations of indices have significant skill in predicting directional wave climates (R² = 0.45–0.8; p < 0.05). We demonstrate for the first time the significant explanatory power of leading winter‐averaged atmospheric indices for directional wave climates, and show that leading seasonal forecasts of the NAO skillfully predict wave climate in some regions.

The two primary causes of surf zone injuries (SZIs) worldwide, including fatal drowning and severe spinal injuries, are rip currents (rips) and shore-break waves. SZIs also result from surfing and bodyboarding activity. In this paper we address the primary environmental controls on SZIs along the high-energy meso–macro-tidal surf beach coast of southwestern France. A total of 2523 SZIs recorded by lifeguards over 186 sample days during the summers of 2007, 2009 and 2015 were combined with measured and/or hindcast weather, wave, tide, and beach morphology data. All SZIs occurred disproportionately on warm sunny days with low wind, likely because of increased beachgoer numbers and hazard exposure. Relationships were strongest for shore-break- and rip-related SZIs and weakest for surfing-related SZIs, the latter being also unaffected by tidal stage or range. Therefore, the analysis focused on bathers. More shore-break-related SZIs occur during shore-normal incident waves with average to below-average wave height (significant wave height, Hs = 0.75–1.5 m) and around higher water levels and large tide ranges when waves break on the steepest section of the beach. In contrast, more rip-related drownings occur near neap low tide, coinciding with maximised channel rip flow activity, under shore-normal incident waves with Hs >1.25 m and mean wave periods longer than 5 s. Additional drowning incidents occurred at spring high tide, presumably due to small-scale swash rips. The composite wave and tide parameters proposed by Scott et al. (2014) are key controlling factors determining SZI occurrence, although the risk ranges are not necessarily transferable to all sites. Summer beach and surf zone morphology is interannually highly variable, which is critical to SZI patterns. The upper beach slope can vary from 0.06 to 0.18 between summers, resulting in low and high shore-break-related SZIs, respectively. Summers with coast-wide highly (weakly) developed rip channels also result in widespread (scarce) rip-related drowning incidents. With life risk defined in terms of the number of people exposed to life threatening hazards at a beach, the ability of morphodynamic models to simulate primary beach morphology characteristics a few weeks or months in advance is therefore of paramount importance for predicting the primary surf zone life risks along this coast.

Records of beach morphologic change and concurrent hydrodynamic forcing are needed to understand how coastlines in different environments change over time. This submission contains data for the period 2006 to 2021, for two contrasting macrotidal environments in southwest England: (i) cross-shore dominated, dissipative, sandy Perranporth Beach, Cornwall; and (ii) longshore-dominated, reflective gravel beaches within Start Bay, Devon. Data comprise monthly to annual beach profile surveys, annual merged topo-bathymetries, in addition to observed and numerically modelled wave and water levels. These data provide a valuable resource for modelling the behaviour of coastal types not covered by other currently available datasets.

We analyze Eulerian and Lagrangian measurements of wave‐induced circulation collected during a 3‐week field experiment at a high‐energy mesotidal barred beach with the presence of a 500‐m headland and a submerged reef. Small changes in wave and tide conditions were found to largely impact circulation patterns. Three main regimes were identified depending on offshore wave obliquity: (1) Under shore‐normal configuration, the flow was dominated by cross‐shore motions, except for moderate waves at low tide, with the presence of a quasi‐steady circulation cell on the reef. (2) Under shadowed configuration, an onshore‐directed current flowing away from the headland and a weak oscillating eddy were present outside and inside the shadow region, respectively. (3) Under deflection configuration, a deflection rip flowing against the headland and extending well beyond the surf zone was present, with activity maximized around low tide for moderate waves. Under 4‐m oblique waves, the deflection rip was active regardless of the tide with mean depth‐averaged velocities up to 0.7 m/s 800‐m offshore in 12‐m depth, with energetic low‐frequency fluctuations. Our results emphasize the ability of deflection rips to transport materials far offshore, suggesting that such rips can transport sediment beyond the depth of closure. This study indicates that a wide variety of wave‐driven circulation patterns can occur and sometimes coexist on beaches with prominent geological settings. Changes in the dominant driving mechanism can occur as a result of small changes in wave and tide conditions, resulting in more spatially and temporally variable circulation than along open sandy beaches.