Article

Characterizing surf zone injuries from the five most populated beaches on the Atlantic-fronting Delaware coast

a b s t r a c t

Introduction: Beaches are a popular destination for recreation activities. Surf zone injuries (SZI) can occur resulting from a variety of in-water activities. Little is known regarding the sustained injury types, or demo- graphics of injured persons and activities leading to injuries.

Methods: This study examines the distribution of SZI types, activities and populations occurring on Delaware Beaches as recorded by a local level III trauma center (Department of Emergency Medicine at Beebe Healthcare in Lewes, Delaware).

Results: There were 2021 injuries over the eight study years (2010-2017). The relative demographics of the injured population are similar despite fluctuating injury totals (mean [SD], 253.1 [104.4]). Non-locals (n = 1757) were 6.7 times more likely to be injured as their local (n = 264) counterparts (RR, 2.62; 95% CI, 2.08- 3.31). Males (n = 1258) were 1.7 times more likely to be injured than their female (n = 763) counterparts (RR, 1.29; 95% CI, 1.21-1.37). Serious injuries, defined as patients requiring admission to a trauma service, repre- sented 9.1% (n = 184) of injuries. Fatal SZI (n = 6) were categorized as serious injuries. Wading (50.1%) was found to be the dominant activity associated with injury followed by body surfing (18.4%), and body boarding (13.3%).

Conclusion: To the authors’ knowledge, this study is one of the first to investigate long-term trends in SZI data, injury activity, and demographics. Better understanding of the characteristics of injuries will allow for improved awareness techniques, targeted at populations with higher injury rates.

(C) 2017

Introduction

Beaches are widely associated with tourism and recreation. People visiting beaches as tourists are often unaware or unfamiliar of oceanic processes, resulting in neglect of beach dangers [1]. Lack of awareness of potential beach hazards is problematic and results in several hundred injuries to water users each summer in Delaware alone [2]. Water users (WU) were defined as those beachgoers who were clearly in the water and potentially at risk of injury. Surf zone injuries (SZI) range in severity from minor sprains and fractures to life altering spinal injuries and even fatalities [2]. The financial cost to injured persons and their family can vary from a few thousand dollars for an isolated emergency department visit to millions of dollars in lifetime medical care for patients left with permanent disabilities [3]. The emotional damage can be devastating, especially in the case of permanent disability or fatality.

* Corresponding author at: 259 Academy Street, Newark, DE 19716, USA.

E-mail addresses: [email protected] (M.B. Doelp), [email protected] (J.A. Puleo), [email protected] (M. Arford-Granholm).

Delaware beaches are guarded between the hours of 0900 and 1700, seven days a week from Memorial Day (last Monday of May) until Labor Day (first Monday in September). They are heavily used with estimated summer attendance at five of the most populated beaches exceeding 7.5 million persons [4]. Puleo et al. [2] estimated 1-2.5 WU per linear meter of beach on crowded days. SZI occurring at beaches other than the five most populated beaches included in the study represented only b 0.2% of the total injuries recorded. Delaware beaches receive visitors from many states and countries. However, most visitors arrive from upstate Delaware, or the surrounding Mid-Atlantic states of Virginia, Maryland, Pennsylvania, and New Jersey.

Previous studies involving beach risks identified hazards both inter- nationally and in the United States (USA). The majority of past research involved rip currents and investigated drowning occurrences [5-7]. Rip currents are estimated to be the source of 80% of beach related rescues in the USA [4]. However, rescues might not be as prevalent in locations like DE, due to the local morphology and hydrodynamics. For example, in 2016 there were 26 SZI and 13 rip-related rescues at Dewey Beach, DE [4]. There has been some research on surf-related injuries resulting from activities such as shallow water diving [8-12], surfing or body boarding

https://doi.org/10.1016/j.ajem.2017.12.053

0735-6757/(C) 2017

[10,12-17], wind surfing [18], and skim boarding [19]. Hoag Hospital, Orange County, CA has collected SZI data for over 30 years. However, Hoag’s medical data collection was limited to spinal column and cord in- juries only. Long term data documenting demographics of SZI popula- tion are needed to draw inferences about the injured population. The present study uses eight years of data to better understand Delaware SZI statistics.

Methods

Data source

Injury data along the Atlantic-fronting Delaware coast from the five most populated beaches (Fig. 1) were collected by the Department of Emergency Medicine at Beebe Health Care in Lewes, DE (ACS Level III trauma center). Survey data did not include physical characteristics of the patients, but did provide demographic details (Section 2.2). Demo- graphics of the injured populations were used to assess similarities be- tween years and determine higher risk groups. However, it is important to determine if the higher risk of a group was due to disproportionate populations in the water, or due to a behavioral component of that group. Population data of WU were collected by researchers on the beach between the summers of 2014 and 2016. One weekday population count and one weekend count were taken each summer to estimate the daily variation of WU throughout the day. Two WU counts were taken at hourly intervals between 0900 and 1700 (guarded hours) and averaged. For practical purposes, counts were taken along a fixed 100-m alongshore stretch of each beach near a beach access point and in direct vicinity of a beach patrol stand. The summer counts were then averaged to estimate the distribution of WUs during a weekday and weekend day. The number of males and females in the water along the same stretch of beach was also counted once daily between the hours of 1300 and 1500. The daily counts between 1300 and 1500 were then extrapolated to total daily counts using the daily counts

variation (see [2] for complete description of methodology).

Questionnaires were distributed to beachgoers during the 2016 and 2017 summer seasons to quantify population demographics on the beach in relation to injured and WU populations. Questionnaires were filled out by individuals over the age of 18, who either were at the beach while responding to the questions, or had attended a Delaware

beach at some point during the summer. Beachgoers are defined as in- dividuals that completed a questionnaire, but did not necessarily enter the water.

Study variables

Injury patient demographic and medical information were extracted by the trauma registrar from Beebe Healthcare. Patient data include, for example, time of injury, activity, age, gender, zip code, and location of injury. Injury activity was grouped into eight categories: wading, body surfing, body boarding, skim boarding, diving, surfing, swimming and other. Of the 47 “other” injuries, six were rafting or tubing, four were kayaking, and two were paddle-boarding. The other 35 injuries were re- corded as “unknown” by the trauma registrar. Wading injuries, defined as injuries occurring while the individual is standing in shallow water (b 1 m), were considered “low risk” SZI. These injuries resulted from the WU being in the water, and not by participating in a sporting activity in the surf. Injured individuals were considered locals if their docu- mented zip code began with a 199XX (southern Delaware zip codes). Serious injuries were categorized as patients requiring admission to a trauma service.

The geographic location of the injury occurrence was recorded as one of the five most populated Atlantic-fronting Delaware beaches (Cape Henlopen State Park, Rehoboth Beach, Dewey Beach, Delaware Seashore State Park, and Bethany Beach; Fig. 1). WU population counts provided estimates as to the distribution of individuals in the water at different times during the day to compare with timing of injury. Beach- goers questionnaires determined the age, gender, home zip code, and number of family members of surveyed persons on the beach. An addi- tional question also asked whether or not the person had observed rip current-related material, SZI, or shore break warnings.

Data analysis

Data are reported with descriptive statistics as case counts, means, medians, standard deviations, standard error (SE), and percentages to describe the injury sample and patterns. Demographics are organized by injury activity, and reported as distributions by age, gender, and local vs. non-local. Statistical analyses were conducted using MATLAB (version R2016b; The MathWorks, Inc., Natick, MA). Estimates of

Fig. 1. a The state of Delaware along with neighboring states and the Delaware Bay. b The Atlantic-fronting shoreline of Delaware showing the five study beaches.

temporal trends“>Fig. 2. Weekday hourly variation of WU Population (2014-2016) against percentage of hourly injury occurrence.

beach population demographics were made with beachgoer question- naires for ?2 goodness of fit analysis (p b 0.05) and Relative risk ra- tios. Statistical analysis also included significance of mean t-tests and z- tests between proportions.

Results

Population and Temporal Trends

Injury data were used to better understand the injured population demographics and long-term trends. Hourly injury distributions for weekends and weekdays were plotted against averaged hourly WU dis- tributions at each of the five beaches (Figs. 2 and 3). Peak hours of WU populations occurred between the hours of 1300 and 1500 for both weekends (50.8%) and weekdays (49.2%). None of the average hourly WU counts were normally distributed (p b 0.001).

WU counts were supplemented with population distribution esti- mates of beachgoers that were derived using the questionnaires handed out to beachgoers. The percent distribution of injuries to each popula- tion were separated by year of occurrence (Table 1). Each year, there was minimal fluctuation in the demographics of the injured population including gender (? = 4.7%; ? is standard deviation) and local vs. non- local (? = 3.4%). The differences of the injury percentage for different age groups relative to the total injured population ranged from 1.3% to

12.4%. For example, the injury percentage for the 41-50 age group was 8.7% in 2017 and 21.1% in 2010 (range = 12.4%).

Gender

The total numbers of injuries to each population were separated by injury activity (Table 2), including the number and type of injuries oc- curring to males and females. Daily WU population counts at the five beaches between 2015 and 2016 indicated that 50.7% of the WU popu- lation was male and 49.3% of the WU population was female. Statisti- cally similar Gender distributions between the WU population (50.8% male) and beachgoer population (52.9% male) suggest the demo- graphics of the two populations are comparable.

There was significant difference between the WU population pro- portions and injured population proportions (p b 0.001). Roughly 63% of the 2021 injuries between 2010 and 2017 were sustained by males (n = 1258) with 37.2% sustained by females (n = 763). The proportion of each injury activity for different populations of interest was separated (Fig. 4). Injury data were also categorized by low risk (e.g., wading) and high risk (e.g., body boarding, body surfing, skim boarding) activity (Fig. 5). Injuries sustained by the female population mostly occurred during low risk activities; wading injuries (70.6%, n = 523; RR, 1.76; 95% CI, 1.62-1.92). The male population had a higher percentage of in- juries occur from more risky activities (60.3%, n = 744; RR, 1.94; 95%

Fig. 3. Weekend hourly variation of WU Population (2014-2016) against percentage of hourly injury occurrence.

Table 1

Injury demographics and beachgoer population (as %) by year.

Demographic

Injuries by

year

Total injuries

Beachgoer population

2010

2011

2012

2013

2014

2015

2016

2017

Gender

Male

65.2

64.9

60.3

64.9

66.4

56.7

59.7

53.2

62.2

52.9

Female

34.8

35.1

39.7

35.1

33.6

43.3

40.3

46.8

37.8

47.1

Zip-code

Non-local

82.2

87.9

92.5

82.9

86.9

88.1

90.1

83.3

86.9

61.7

Local

17.8

12.1

7.5

17.1

13.1

11.9

9.9

16.7

13.1

38.3

Age

0-10

10.8

7.0

8.3

12.6

11.2

7.3

7.7

17.5

9.5

14.9

11-20

26.6

32.3

26.6

29.7

29.1

26.1

25.3

29.4

28.2

22.1

21-30

10.8

10.6

11.9

12.6

11.6

9.4

10.7

7.1

10.7

14.2

31-40

11.3

12.1

10.7

10.8

11.6

13.5

14.6

9.5

11.9

12.0

41-50

21.1

17.3

15.9

16.2

14.6

19.6

13.7

8.7

16.8

13.0

51-60

12.3

10.9

17.1

7.2

13.4

12.7

13.7

12.7

12.7

12.6

61-70

5.0

7.5

6.7

8.1

6.7

8.6

11.2

11.9

7.7

9.2

71 +

2.3

2.3

2.8

2.7

1.9

2.9

3.0

3.2

2.5

1.9

Activity

Wading

55.6

45.5

52.4

48.6

45.1

48.6

51.9

53.2

50.1

Body boarding

14.5

20.9

20.6

16.2

19.8

16.7

17.2

22.2

18.4

Body surfing

9.5

14.5

10.3

15.3

17.5

16.7

12.4

11.9

13.3

Skim boarding

5.3

7.5

3.6

2.7

6.0

5.7

5.2

7.1

5.6

Swimming

2.3

4.7

5.6

4.5

4.5

7.8

4.7

0.8

4,4

Surfing

5.0

4.1

4.4

7.2

2.2

1.2

2.1

0.8

3.5

Diving

3.0

0.5

1.6

4.5

3.7

2.0

3.9

2.4

2.5

Other

4.8

2.3

1.6

0.9

1.1

1.2

2.6

1.6

2.3

Total injuriesa

19.7

19.1

12.5

5.5

13.3

12.1

11.5

6.2

a Row contains proportion of total injuries for the year.

CI, 1.73-2.18). The activities in which males had a higher percentage of injuries than females include: body surfing (84.4%), body boarding (73%), skim boarding (85%), diving (78%), and surfing (80%). Serious in- juries (88%) were predominantly sustained by males (RR, 4.47; 95% CI, 2.89-6.91).

Age

The age of the 2021 injured individuals ranged from 1 to 88 years (mean [SE], 33.5 [0.44] years; median 32 years). The average age of fe- males (mean [SE], 36 [0.74] years; median 37 years) was higher than males (mean [SE], 32 [0.44] years; median 28.5 years). A two-sample t-test indicated a significant difference of mean injury age between males and females (p b 0.001). There are trends in the distribution of in- juries across age groups for each year. All eight study years portrayed a similar bimodal distribution with peaks in the 11-20 and 41-60 (in- cludes both 41-50 and 51-60) age groups (Table 2). The 11-20 age

group accounted for 20%-30% of all injury activities except skim boarding (65.5%). There was significant relative risk for that age group (RR, 1.14; 95% CI, 1.07-1.21) compared to the beachgoer population. The only other age groups that had a relative risk greater than 1 was the 41-60 age group (RR, 1.08; 95% CI, 1.03-1.14).

There was significant difference between injured and beachgoer population percent distributions for the 0-10, 11-20, 21-30, and 41- 50 age groups (p b 0.001). Alternatively there was no significant differ- ence between the two populations for the 31-40, 51-60, 61-70, and older than 71 age groups (e.g., 51-60 injured population = 12.7% and beachgoer population = 12.6%).

Locals vs. non-locals

A majority of SZI occurred to non-locals (RR, 2.62; 95% CI 2.08-3.31) both for the entire injured population (86.9%), and for individual injury activities (Table 2). Of the injured wader population, 89.6% (n = 907)

Table 2

Injury activity based on demographics (n = 2021).

Demographic

Activity

Total

Wading

Body boarding

Body surfing

Skim boarding

Swimming

Surfing

Diving

Other

n = 2021

n = 1012

n = 371

n = 269

n = 113

n = 89

n = 70

n = 50

n = 47

Gender

Male

1258

489

271

227

96

55

56

39

25

Female

763

523

100

42

17

34

14

11

22

Zip-code

Non-local

1757

907

334

241

85

64

53

41

32

Local

264

105

37

28

28

25

17

9

15

Age

0-10

193

101

55

8

17

5

3

1

3

11-20

569

225

116

75

74

22

23

23

11

21-30

216

86

33

34

14

17

13

11

8

31-40

241

120

51

32

3

11

13

5

6

41-50

339

176

64

51

5

10

14

6

13

51-60

257

151

43

40

0

16

4

1

2

61-70

155

110

8

27

0

5

0

3

2

71 +

51

43

1

2

0

3

0

0

2

Fig. 4. Distribution of injury activity for: a Female b Male c Non-Local d Local e 11-20 Age Group f 41-60 Age Group and g Serious Injuries. Injury percentages b6% are not labeled.

were defined as non-locals. Locals accounted for just 10.4% (n = 105) of the total wading injuries. The local injured population was more likely to sustain an injury in a higher risk activity such as body surfing (35.7%) or skim boarding (24.8%). The proportion of non-locals to locals for low risk activities (8.6:1) is significantly greater than the overall in- jured population of non-locals to locals (p b 0.01). The proportion of non-locals to locals for high risk activities (4.0:1) is significantly less than the overall injured population of locals to non-locals (p b 0.001).

There were 1.6 times as many non-locals compared to locals as iden- tified by beachgoer surveys (n = 1455). A two-sample z-test indicated significant difference between the local to non-local ratios for the in- jured population and beachgoer population (p b 0.001) indicating that non-locals are injured at a higher proportional rate.

Data on wading WU orientation (facing waves or back to waves) at the time of injury was also recorded from 2015 to 2017. Of the wading injuries, 72.4% (n = 113) of the WU had their back to the waves. Of the total back to wave injuries, 85.4% (n = 97) were non-locals. It is un- known for prior years what percentage of wading injuries were related to WU having their backs to the waves.

Discussion

Higher risk demographics

To the authors’ knowledge, this study is one of only a few investigat- ing the population demographics of SZI data across surf zone activities. Other SZI research focused on the demographics of spinal SZI in Ocean City, MD [12] or on a single activity basis such as surfing [17]. Previous research based on a subset of these data [2] were consistent with the de- mographics of the aggregate data analyzed in this paper. The number of injuries fluctuated from year to year (standard deviation [SE], 104.4 [36.9]), but the individual year demographics were consistent with the aggregate data.

Injuries sustained by males accounted for nearly two-thirds of the total injuries (62.2%), similar to prior studies involving beach hazards [20]. The 22.7% increase in percentage between injured males and male WU suggests a difference in the behavior of males and females that is apparent in similar surf hazard studies [2,6,9,10,13-15,17,21, 22]. Only 39.2% of the total male injuries were associated with wading compared to 69.0% of female injuries. Males were more likely to be in- jured as a result of more risky activities like skim boarding (85.0%), body surfing (84.4%), and surfing (80.0%). Increased risk taking by males partially explains differences in observed injury activity between genders [22].

Three main age groups accounted for over half of the injured popu- lation, the 11-20 (26.1%) and the 41-60 age groups (30.9%). SZI in the 11-20 age group are more commonly associated with high risk activities (e.g., skim boarding, body surfing, body boarding), and reflect the behavior of persons in that age group. Similar high numbers of Australian surf rescues [22] have been documented for males in the 11-30 age group. However, the Australian study found a maximum number of injuries between 20 and 29 years, an age group that accounts for only 10.7% of SZI in this study and does not have a significant risk (RR, 0.87; 95% CI, 0.79-0.95). Male non-locals in the age group of 11- 20 are much more likely (22.0% of total injuries) to sustain injury rela- tive to other populations (RR, 1.17; 95% CI, 1.13-1.21). The lower age group peak for SZI in this study indicates a potential lack of beach safety education, assuming risk perception is held constant. Safety awareness and injury prevention discussions including concepts of oceanic processes could be provided during classroom or physical education ac- tivities to reach the largest number of individuals in the 11-20 age group and not limited to just coastal communities.

The numerous SZI in the 41-60 age groups were responsible for the

greater mean age for this study (mean = 33.5 years) relative to other SZI studies with mean ages in the range of 22-29 [8,9,12,13,15,17]. The proportion of SZI for individuals in the 41-60 age groups are 1.4

times greater than rip-related fatalities [6], and 1.6 times greater than surfing injuries [17] and warranted further research (as described in [2]). Beachgoer questionnaires conducted in 2016 indicated that most individuals in the 41-60 year old range came to the beach with children (88.4%). Wading injuries represented the most common activity prior to injury for injured persons in this age group. One possible explanation of the high injury rate in this age group is associated with parents paying more attention to their children than the waves while standing in b 1 m. of water. The rates of other types of SZI for this age group could be low because older WU tend to participate in less risky activities. Recommendations of methods to reduce injuries to this age group are similar to those catered to non-locals in Section 4.2.

Injuries to non-locals and targeted awareness

The number of injuries sustained by non-locals was over six times greater than the number of injuries sustained by locals (n = 1757 vs. n = 246). Results from other beach studies also suggest that non-locals are more likely to put themselves at risk [1,2,23]. Those studies did not report beach or WU demographics to compare to the injury data set. The locals to non-locals ratio for the injured population (6.7) had a 57.7% in- crease over the ratio of locals to non-locals of beachgoers (2.6). The number of wading injuries sustained by non-locals was 8.7 times the number of wading injuries (n = 907 vs. n = 105) sustained by locals. The difference in the proportion of injured wading population and the beachgoer population points to a possible lack of knowledge of ocean processes (or ability in the ocean) of the non-local population. Of the surveyed beachgoers, about half of the non-locals surveyed (52.2%) had seen rip-current-related information but a smaller percentage had seen any information about SZI or shore break warnings (16.6%). Educa- tional awareness materials directed at non-locals may help reduce SZI [2], especially low-risk injuries. A targeted awareness campaign, de- voted to providing SZI awareness and prevention knowledge to non-lo- cals (the highest proportion of wading injuries and injuries with back to waves) could be an effective means to decreasing the number of low risk activity SZI. Possible education material includes signage on beaches and/or beach safety pamphlets distributed at coastal realty agencies. Awareness to reduce high risk activity injury rates must be treated differently as they are tied to risk perception [24]. In high risk activity injuries, the individual likely knows the inherent risks associ- ated with the activity and the authors’ believe alternative awareness methods should be taken.

Future work

Long-term documentation of SZI is important in recognizing tempo- ral injury trends and for developing awareness strategies for beach safety. The consistency of long-term demographics at Atlantic-fronting Delaware beaches suggest safety awareness campaigns be directed at particular populations (e.g., non-locals, youth, males). Beach patrol ultimately influence SZI through awareness and the administration of initial medical care. The administration of aid may reduce the injury se- verity, but awareness and educational efforts influence SZI rate [12]. Routine evaluations of SZI demographics allow beach patrol to monitor groups that are injured in higher proportions, to ensure proper aware- ness and education efforts are allocated effectively.

Other possible uses of the injury data set include a temporal compar- ison of the injury occurrence to the environmental conditions at the time of injury [2]. These comparisons would allow for a better under- standing of when injuries are more likely to occur, and assist beach patrol in alerting beachgoers of dangerous conditions. Enhanced knowledge of the relationship between environmental conditions and the type of activity resulting in injury may assist beach patrol decision making. For example, beach patrol could restrict particular activities in the surf until conditions change. This application is best suited for the reduction of high risk activity injuries.

Fig. 5. High risk and low risk activities based on demographic.

Study limitations

Study limitations include the possibility of missing data and that data are limited by the detail provided by patients to the trauma regis- trar and assistants. Characteristics of the injury such as activity might be incorrectly documented as the record is dependent on the recount of the event. Beebe Healthcare does not follow up with injured individuals to determine a final disposition. Thus, any change in disposition related to SZI after initial disposition (e.g., admitted, transferred to a higher level of care) are unknown.

Also, injured individuals may have decided to not go to Beebe and go home or to an alternate medical facility. Consequently, some popula- tions might be underrepresented in the study, altering the injury distri- bution. Some injury data from locals may be unaccounted for because locals may be more likely to seek care at their primary care office or other Healthcare facility. The potential lack of locals in the data set can inflate the proportion of non-locals recorded. However, the year to year consistency of the data suggests missing SZI reports would be a small component of the study. Future work might try to compare re- cords of injuries by beach patrol and at Beebe Healthcare to quantify the percentage of injured persons missing in the Beebe Healthcare data set. Another possibility is to initiate partnerships with smaller local healthcare facilities to document SZI.

Conclusion

To the authors’ knowledge, this study is one of a few investigating demographics of SZI. The numerous injuries to non-locals, and predict- ability of injury demographics each year indicate a need for increased Prevention efforts and awareness. Many of these injuries occur during low risk activities that are preventable with basic knowledge. Beachgoer questionnaires suggest knowledge for non-locals is lacking as only 16.6% of those surveyed had seen information about SZI or shore

break warnings. Future SZI studies should consider measuring the effec- tiveness of awareness methods for different populations and long-term reduction in injuries.

Sources of support

Delaware Sea Grant (grant no. NA14OAR4170087), the Delaware Department of Natural Resources and Environmental Control and the University of Delaware. The authors also would like to acknowledge local town managers and those individuals that assisted with counting beach populations.

Conflict of interest statement and disclaimer

Interpretations and conclusions expressed in this article are unbi- ased, and the authors have no financial or other conflicts of interests to disclose. Opinions in this article do not represent those of the funding organizations or the University of Delaware.

Ethical considerations

All injury data from Beebe Healthcare were anonymous and followed all HIPAA compliances. No data identifying injured persons were recorded. Beebe Healthcare followed IRB protocol and obtained proper approval.

Acknowledgements

The authors gratefully acknowledge support from Delaware Sea Grant (grant no. NA14OAR4170087), the Delaware Department of Natural Resources and Environmental Control and the University of Delaware. The statements, findings, and conclusions are those of the authors and do not necessarily reflect the views of those organizations. The authors also would like to acknowledge local town managers and

those individuals that assisted with counting beach populations. Inter- pretations and conclusions expressed in this article are unbiased, and the authors have no financial or other conflicts of interests to disclose.

References

  1. Ballantyne R, Carr N, Hughes K. Between the flags: an assessment of domestic and international university students’ knowledge of beach safety in Australia. Tour Manag 2005;26(4):617-22.
  2. Puleo JA, Hutschenreuter K, Cowan P, Carey W, Arford-Granholm M, McKenna KK. Delaware surf zone injuries and associated environmental conditions. Nat Hazards 2016;81(2):845-67.
  3. Cao Y, Chen Y, DeVivo M. Lifetime direct costs after spinal cord injury. Top Spinal Cord Inj Rehabil 2011;16(4):10-6.
  4. USLA. United States Lifesaving Association – statistics. Available at: http://arc.usla. org/Statistics/current.asp?Statistics=5; 2016. [Online, cited 2017].
  5. Brander R, Bradstreet A, Sherker S, MacMahan J. Responses of swimmers caught in rip currents: perspectives on mitigating the global rip current hazard. Int J Aquat Res Educ 2011;5(4).
  6. Gensini VA, Ashley WS. An examination of rip current fatalities in the United States. Nat Hazards 2010;54(1):159-75.
  7. McCarroll RJ, Brander RW, MacMahan JH, Turner IL, Reniers AJHM, Brown JA, et al. Evaluation of swimmer-based rip current escape strategies. Nat Hazards 2014;71 (3):1821-46.
  8. Beratan K, Osborne R. Frequency and demographic aspects in shallow-water diving accidents in Southern California. Shallow-water Diving Accidents at Southern Califor- nia Ocean Beaches: Demographic, Sedimentologic, Medical, Legal and Management Perspectives. Los Angeles, CA: Osborne RH University of Southern California; 1987.
  9. Aito S, D’Andrea M, Werhagen L. spinal cord injuries due to diving accidents. Spinal Cord 2004;43(2):109-16.
  10. Chang SKY, Tominaga GT, Wong JH, Weldon EJ, Kaan KT. Risk factors for water sports-related Cervical spine injuries. J Trauma Acute Care Surg 2006;60(5).
  11. Robles LA. Cervical spine injuries in ocean bathers: wave-related accidents. Neuro- surgery 2006;58(5):920-3.
  12. Falcon J. Evaluating Near Shore Spinal Injuries and Alternatives to Reduce their Occurrence. Baltimore, MD: University of Maryland Baltimore County; 2016.
  13. Nathanson A, Haynes P, Galanis D. Surfing injuries. Am J Emerg Med 2002;20(3): 155-60.
  14. Barucq G, Jenkins O, Mokni T, Marce J-M, Campagne D, Le Jeune D. Surfing-related accidents: epidemiology and prevention. Available at: http://blog.surf-prevention. com/2009/01/21/surfing-related-accidents-epidemiology-and-prevention/; 2009.

    [cited 2016].

    Hay CSM, Barton S, Sulkin T. Recreational surfing injuries in Cornwall, United Kingdom. Wilderness Environ Med 2009;20(4):335-8.

  15. Meir RA, Zhou S, Rolfe MI, Gilleard WL, Coutts RA. An investigation of surf participa- tion and injury prevalence in Australian surfers: a self-reported retrospective analy- sis. N Z J Sports Med 2012;39(2):52.
  16. Klick C, Jones CM, Adler D. Surfing USA: an Epidemiological study of surfing injuries presenting to US EDs 2002 to 2013. Am J Emerg Med 2016;34(8):1491-6.
  17. Kalogeromitros A, Tsangaris H, Bilalis D, Karabinis A. Severe accidents due to wind- surfing in the Aegean Sea. Eur J Emerg Med 2002;9(2).
  18. Williams MR, Poulter RJ, Fern ED. Skimboarding: a new danger in the surf? Emerg

    Med J 2006;23(2):137.

    Pollard KA, Gottesman BL, Rochette LM, Smith GA. Swimming injuries treated in US EDs: 1990 to 2008. Am J Emerg Med 2013;31(5):803-9.

  19. Williamson A, Hatfield J, Sherker S, Brander R, Hayen A. A comparison of attitudes and knowledge of beach safety in Australia for beachgoers, rural residents and inter- national tourists. Aust N Z J Public Health 2012;36(4):385-91.
  20. Morgan D, Ozanne-Smith J. Surf lifeguard rescues. Wilderness Environ Med 2013;24

    (3):285-90.

    Klein A da F, Santana G, Diehl F, De Menezes J. Analysis of hazards associated with sea bathing: results of five years work in oceanic beaches of Santa Catarina state, southern Brazil. J Coast Res 2003:107-16.

  21. M JP, Moran K, Ameratunga S, Robinson E. New Zealand Beachgoers’ Swimming Behaviors, Swimming Abilities, and Perception of Drowning Risk; 2008.

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