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The potential for rescues and drownings is dependent on the spatial and temporal correspondence of an active rip current with the distribution of vulnerable beach users. This short communication examines the alongshore correspondence among the (1) exit locations of the walkovers, (2) the spatial and temporal distribution of beachgoers, and (3) the position of semipermanent accretion rips at Pensacola Beach, Florida. Results suggest that the alongshore distribution of beach users on the beach and in the water corresponds to the location of beach access points, which during this period of time sit directly landward of the three rip channels visible in the camera frame during the busy summer season of 2010. Assuming that the majority of beach users are unable to identify a rip current and avoid the hazard, the selection of swimming locations based on convenience suggests that beach safety efforts need to focus on guiding beach users to relatively safe locations away from rip current activity. [ABSTRACT FROM AUTHOR]

ABSTRACT There is a paucity of field data to describe the transition in nearshore circulation between alongshore, meandering and rip current systems. A combination of in-situ current meters and surf zone drifters are used to characterize the nearshore circulation over a transverse bar and rip morphology at Pensacola Beach, Florida in the presence of relatively low energy oblique waves. Current speeds vary in response to the relative wave height ratio ( Hs/h), which defines the degree and extent of breaking over the shoal. In the absence of wave breaking the nearshore circulation was dominated by an alongshore current driven by the oblique waves. As waves begin to break across the shoal (0.2< Hs/ h<0.5) the nearshore circulation is characterized by a meandering alongshore current. As conditions became more dissipative ( Hs/h>0.5), the meandering current is replaced by an unsteady rip circulation that moves offshore between the shoals before turning alongshore in the direction of wave advance outside the surf zone. The increase in wave dissipation is associated with an increase in very low frequency (VLF) variations in the current speed across the shoal and in the rip channel that caused the circulation to oscillate between an offshore and an alongshore flow. The unsteady nature of the nearshore circulation is responsible for 55% of all surf zone exits under these more dissipative conditions. In contrast, only 29% of the drifters released from the shoal exited the surf zone and bypassed the adjacent shoal with the alongshore-meandering current. While the currents had a low velocity (maximum of ~0.4 m s-1) and would not pose a significant hazard to the average swimmer, the results of this study suggest that the transverse bar and rip morphology is sufficient to create an alongshore variation in wave dissipation that forces alongshore meandering and low-energy rip circulation systems under oblique wave forcing. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Quasi-permanent rip current hot spots at Pensacola Beach, Florida, pose a significant hazard to beach users, largely because the hot spots are located at or close to the primary access points. While an increase in the number of lifeguards has led to a decrease in the number of drownings since 2004, the number of rescues and contacts has increased to over a 30,000 year. Despite warning signs at access points along the beach, it is not clear whether beach users are able to identify a rip channel or an active rip current. To assess beach users' knowledge of rip currents and their ability to identify rip channels and currents, 97 surveys were conducted between June and September of 2010 at Pensacola Beach. Beach users were asked to identify rip channels in oblique photographs taken on green, yellow and red flag days when the potential for rip currents is low, medium and high, respectively. A majority of participants suggested that they could identify a rip channel or current (if present), but less than 20 % of beach users were able to identify the rip channels and currents. The majority of participants identified heavy surf areas as the location of the rips versus the relatively flat water of the current or the darker color water of the channel. Results further suggest that most beach users, and particularly local participants, are overconfident in their ability to identify rip channels and currents. The focus of beach users on heavy surf as an indication of the rip current potential and the overconfidence in identifying a rip channel or current affects the spatial distribution of beach users and to some degree the location of rescues and drownings. While it can be quite difficult for the average beach user to identify rip channels and active rip currents, the results of the study suggest a need for further education efforts to reduce the rip hazard, particularly in areas where lifeguards are not permanently stationed. [ABSTRACT FROM AUTHOR]

Rip currents at Pensacola Beach in northwest Florida are associated with a transverse bar and rip morphology that develops as the nearshore bars migrate landward and weld to the beachface. As shown in a number of recent studies, the nearshore bar morphology at Pensacola Beach varies alongshore in response to a ridge and swale bathymetry on the inner-shelf, creating "hotspots" of rip current activity. However, it remains unclear whether these recently identified "hotspots" were present before Hurricane Ivan and if the development of the rip system is a response to the bar cycle. Wavelet analysis of aerial and satellite imagery from 1951 to 2004 was used to quantify the alongshore variation in bar morphology and identify when and where transverse bar and rip morphology develops in response to the storm-driven bar cycle. The innermost bar varies alongshore at a scale (of ∼1000 m) that is consistent with the ridge and swale bathymetry, being closest to the beachface immediately landward of the deeper swales. As the bar migrates landward in the swales, it develops a variation with a length scale (of ∼200 m) that is consistent with the spacing between rip currents. The transverse bar and rip morphology is found to preferentially develop at the primary beach access points where most drownings and rescues have historically taken place. The lack of a transverse bar and rip morphology Iandward of the ridges suggests that the bar cycle is rarely completed (with bar welding to the beachface) at those locations before the next hurricane or tropical storm moves it offshore. [ABSTRACT FROM AUTHOR]