1 00:00:00,740 --> 00:00:03,490 (dramatic music) 2 00:00:12,320 --> 00:00:13,620 There are powerful forces 3 00:00:13,620 --> 00:00:15,770 that move along our beaches. 4 00:00:15,770 --> 00:00:17,240 They pulse. 5 00:00:17,240 --> 00:00:18,870 They flow. 6 00:00:18,870 --> 00:00:21,270 Some can appear without warning, 7 00:00:21,270 --> 00:00:24,760 turning an idyllic beach setting into scenes of chaos, 8 00:00:24,760 --> 00:00:25,593 and panic. 9 00:00:29,400 --> 00:00:33,510 They're masters of camouflage, often hiding tremendous power 10 00:00:33,510 --> 00:00:35,413 within seemingly calm waters. 11 00:00:38,660 --> 00:00:40,963 Here, they wait for the unsuspecting. 12 00:00:42,480 --> 00:00:43,430 And there are many. 13 00:00:45,830 --> 00:00:49,453 The majority of beach-goers can't recognize their danger. 14 00:00:49,453 --> 00:00:52,203 (dramatic music) 15 00:00:54,680 --> 00:00:57,950 I suddenly sensed that I was in a different situation, 16 00:00:57,950 --> 00:00:59,890 that I had never anticipated before. 17 00:00:59,890 --> 00:01:03,500 I mean, it was a surge or a current moving off the shore, 18 00:01:03,500 --> 00:01:06,033 out away from the shore, which I did not expect. 19 00:01:07,173 --> 00:01:08,733 It was like you were in a river. 20 00:01:11,490 --> 00:01:14,288 I'd actually swam myself into a rip current, 21 00:01:14,288 --> 00:01:15,684 without being aware of it. 22 00:01:15,684 --> 00:01:18,434 (dramatic music) 23 00:01:26,880 --> 00:01:29,670 Lou Armstrong was lucky to survive. 24 00:01:29,670 --> 00:01:31,560 If it wasn't for the efforts of his wife, 25 00:01:31,560 --> 00:01:33,740 and a stranger walking the beach, 26 00:01:33,740 --> 00:01:36,140 he would have perished in the rip. 27 00:01:36,140 --> 00:01:38,513 But what exactly is a rip current? 28 00:01:40,560 --> 00:01:44,270 Australian Rob Brander, often called Dr. Rip, 29 00:01:44,270 --> 00:01:47,083 is one of the world's leading experts on rip currents. 30 00:01:49,550 --> 00:01:51,420 Well, let me tell you what rips are not. 31 00:01:51,420 --> 00:01:53,610 They're not undertow, they won't pull you under, 32 00:01:53,610 --> 00:01:55,380 because there's no such thing as an undertow. 33 00:01:55,380 --> 00:01:57,510 They're not rip tides, because they're not a tide. 34 00:01:57,510 --> 00:01:58,410 They're a current. 35 00:02:00,720 --> 00:02:02,930 Powerful currents can appear on any beach 36 00:02:02,930 --> 00:02:07,930 that has breaking waves, and Australia has a lot of beaches. 37 00:02:08,150 --> 00:02:09,783 Almost 11,000. 38 00:02:10,660 --> 00:02:12,440 Less than four percent of these beaches 39 00:02:12,440 --> 00:02:14,563 are actually patrolled by life guards. 40 00:02:16,370 --> 00:02:19,740 So, it's critical that all Australian beach-goers 41 00:02:19,740 --> 00:02:21,790 have a good understanding of the hazards. 42 00:02:25,660 --> 00:02:27,830 The same is true around the world, 43 00:02:27,830 --> 00:02:31,710 including the United States, where more than 12,000 miles 44 00:02:31,710 --> 00:02:35,593 of welcoming coastline creates a perfect storm for tragedy. 45 00:02:38,000 --> 00:02:39,720 Panama City, Florida. 46 00:02:39,720 --> 00:02:42,020 June, 2019. 47 00:02:42,020 --> 00:02:44,470 This compelling footage shows how a group 48 00:02:44,470 --> 00:02:47,973 of swimmers quickly become trapped in the overwhelming flow. 49 00:02:49,000 --> 00:02:52,400 Along with emergency personnel, tenacious bystanders 50 00:02:52,400 --> 00:02:56,300 form a human chain and just barely free the swimmers 51 00:02:56,300 --> 00:02:57,733 from the clutches of death. 52 00:03:01,430 --> 00:03:03,763 And this is far from an isolated incident. 53 00:03:05,649 --> 00:03:06,640 (siren wailing) 54 00:03:06,640 --> 00:03:10,060 Each year, more than 50,000 people are rescued 55 00:03:10,060 --> 00:03:11,640 from rip currents. 56 00:03:11,640 --> 00:03:15,433 But more than 100 drown, struggling to make it to shore. 57 00:03:16,480 --> 00:03:19,950 Surprisingly, even along the Great Lakes, 58 00:03:19,950 --> 00:03:24,183 nearly 300 swimmers have died in rip currents since 2010. 59 00:03:25,400 --> 00:03:28,690 This summer alone, more than 30 swimmers have already 60 00:03:28,690 --> 00:03:30,733 lost their lives on US beaches. 61 00:03:35,230 --> 00:03:38,460 Dr. Rob Brander believes many of these tragic incidents 62 00:03:38,460 --> 00:03:40,640 could have been avoided if people were able 63 00:03:40,640 --> 00:03:43,493 to recognize the signs of an operating rip current. 64 00:03:48,370 --> 00:03:50,140 The simplest way to describe rip currents 65 00:03:50,140 --> 00:03:53,210 is that they're strong, narrow, seaward flowing currents 66 00:03:53,210 --> 00:03:54,820 that extend from the shoreline 67 00:03:54,820 --> 00:03:56,520 out beyond the breaking waves. 68 00:03:56,520 --> 00:03:58,730 And they exist to bring all that extra water 69 00:03:58,730 --> 00:04:02,160 that's coming in with the breaking waves back offshore. 70 00:04:02,160 --> 00:04:04,950 And all of our recent research has shown 71 00:04:04,950 --> 00:04:06,810 that rips are incredibly complex, 72 00:04:06,810 --> 00:04:08,890 and they're much more unpredictable and dangerous 73 00:04:08,890 --> 00:04:10,939 than we could ever have imagined. 74 00:04:10,939 --> 00:04:13,689 (dramatic music) 75 00:04:16,770 --> 00:04:19,600 The best way to spot a rip is to look for dark gaps. 76 00:04:19,600 --> 00:04:21,140 Right behind me, we've got a nice rip, 77 00:04:21,140 --> 00:04:23,190 it looks like a dark gap, almost like a road, 78 00:04:23,190 --> 00:04:25,010 or a path going through the surf. 79 00:04:25,010 --> 00:04:27,170 Now, over here it's a shallow sandbar, 80 00:04:27,170 --> 00:04:30,440 the waves are breaking, all that whitewater is piling up 81 00:04:30,440 --> 00:04:32,670 on the beach, it starts flowing along the beach, 82 00:04:32,670 --> 00:04:35,340 in this deeper channel, then turns the corner, 83 00:04:35,340 --> 00:04:37,240 and that's your rip. 84 00:04:37,240 --> 00:04:38,600 To be able to form, 85 00:04:38,600 --> 00:04:40,670 rip currents need breaking waves. 86 00:04:40,670 --> 00:04:43,520 It's the spatial variation in the breaking waves, 87 00:04:43,520 --> 00:04:46,870 normally caused by undulations in the sand beds, 88 00:04:46,870 --> 00:04:48,960 that commonly begins in the process 89 00:04:48,960 --> 00:04:50,403 of a rip current forming. 90 00:04:51,780 --> 00:04:54,871 A flow develops that moves from the region 91 00:04:54,871 --> 00:04:57,000 of intense wave-breaking, toward the region 92 00:04:57,000 --> 00:05:00,920 of reduced or no wave-breaking inside the surf zone. 93 00:05:00,920 --> 00:05:03,250 This flow is the pathway of least resistance 94 00:05:03,250 --> 00:05:04,603 for the outgoing water. 95 00:05:05,500 --> 00:05:09,253 Often, a perfect channel, just like a river of the sea. 96 00:05:10,110 --> 00:05:13,993 The water flowing out along this channel is the rip current. 97 00:05:15,550 --> 00:05:18,480 The most common type is a channelized rip. 98 00:05:18,480 --> 00:05:21,830 These rips occupy deep channels between sand bars, 99 00:05:21,830 --> 00:05:24,510 and they can stay in the same place for days, 100 00:05:24,510 --> 00:05:26,363 weeks, and even months. 101 00:05:27,770 --> 00:05:29,673 Then, there's boundary rips, 102 00:05:30,590 --> 00:05:33,860 which are found against headlands and other structures, 103 00:05:33,860 --> 00:05:37,133 reaching out into the ocean, like piers and jetties. 104 00:05:38,780 --> 00:05:41,870 But one of the most dangerous and unpredictable rips 105 00:05:41,870 --> 00:05:42,943 is the flash rip. 106 00:05:46,705 --> 00:05:49,040 You can see the chopped up, messy whitewater 107 00:05:49,040 --> 00:05:51,440 that's just gone out, and then it's just stopped. 108 00:05:51,440 --> 00:05:53,740 And that's one common thing about these flash rips, 109 00:05:53,740 --> 00:05:56,020 is they can suddenly occur anywhere 110 00:05:56,020 --> 00:05:58,420 where there's suddenly been a large group of waves breaking 111 00:05:58,420 --> 00:06:01,453 and it pushes the rip out, and then it disappears. 112 00:06:04,320 --> 00:06:06,330 Rob is driven to understand more 113 00:06:06,330 --> 00:06:08,533 about how these deadly currents operate. 114 00:06:11,450 --> 00:06:13,560 To get inside the heart of rip currents, 115 00:06:13,560 --> 00:06:15,593 Rob uses GPS technology. 116 00:06:16,980 --> 00:06:20,800 These instruments are mobile devices called drifters, 117 00:06:20,800 --> 00:06:22,600 and when placed in a rip current, 118 00:06:22,600 --> 00:06:25,970 their onboard GPS units record data that helps Rob 119 00:06:25,970 --> 00:06:27,770 and his team understand more about 120 00:06:27,770 --> 00:06:29,270 what these currents are doing. 121 00:06:32,258 --> 00:06:35,008 (waves crashing) 122 00:06:44,390 --> 00:06:47,320 Over the last decade, these experiments have recorded 123 00:06:47,320 --> 00:06:50,343 hundreds of hours of data, across multiple beaches, 124 00:06:51,270 --> 00:06:54,393 and the research has revealed some astonishing information. 125 00:06:55,280 --> 00:06:58,790 Data from the GPS drifters has revealed so much variation 126 00:06:58,790 --> 00:07:00,870 about how rip currents actually flow. 127 00:07:00,870 --> 00:07:03,970 And really, it's changed everything about what we thought 128 00:07:03,970 --> 00:07:05,720 we knew about rip currents. 129 00:07:05,720 --> 00:07:08,350 The drifter data shows enormous variations 130 00:07:08,350 --> 00:07:10,130 in rip current flow patterns. 131 00:07:10,130 --> 00:07:14,080 Sometimes the rip flow exits well beyond the surf zone, 132 00:07:14,080 --> 00:07:15,090 in the deeper water. 133 00:07:15,090 --> 00:07:17,790 Sometimes it recirculates within the surf zone, 134 00:07:17,790 --> 00:07:20,280 but also that there's dramatic variations 135 00:07:20,280 --> 00:07:22,680 in both flow speed and the direction, 136 00:07:22,680 --> 00:07:24,480 in incredibly short periods of time. 137 00:07:26,270 --> 00:07:28,720 The average rip current flows offshore at speeds 138 00:07:28,720 --> 00:07:31,240 of about half a meter to one meter per second. 139 00:07:31,240 --> 00:07:33,770 But they all have a tendency to pulse. 140 00:07:33,770 --> 00:07:36,110 What that means is that suddenly the rip current 141 00:07:36,110 --> 00:07:37,980 can just dramatically double its speed 142 00:07:37,980 --> 00:07:40,330 in a matter of 30 seconds, and then you're talking 143 00:07:40,330 --> 00:07:42,220 speeds of two meters per second, 144 00:07:42,220 --> 00:07:44,783 which is literally Olympic swimming speeds. 145 00:07:44,783 --> 00:07:47,533 (dramatic music) 146 00:07:48,390 --> 00:07:50,860 For Rob, this information is critical 147 00:07:50,860 --> 00:07:52,710 to helping him answer a key question: 148 00:07:53,620 --> 00:07:57,083 what's the best way to get out of a rip current alive? 149 00:07:58,500 --> 00:08:01,110 (splashing) 150 00:08:01,110 --> 00:08:02,730 So one of the problems with rips, of course, 151 00:08:02,730 --> 00:08:05,290 is no matter what you do, people will always get caught 152 00:08:05,290 --> 00:08:07,500 in rips, and you have to tell them something 153 00:08:07,500 --> 00:08:09,350 about what they should do. 154 00:08:09,350 --> 00:08:11,890 And one of the traditional pieces of advice 155 00:08:11,890 --> 00:08:13,700 that's been around for a long, long time is, 156 00:08:13,700 --> 00:08:15,630 if you get caught in a rip, you should swim parallel 157 00:08:15,630 --> 00:08:18,120 to the beach; it's been there for ages. 158 00:08:18,120 --> 00:08:19,010 But is that true? 159 00:08:19,010 --> 00:08:22,190 Is that one, single piece of advice gonna work 160 00:08:22,190 --> 00:08:24,110 in all situations? 161 00:08:24,110 --> 00:08:27,150 And what our research has shown is that no, 162 00:08:27,150 --> 00:08:29,820 that's not true, and we've got to the point now, 163 00:08:29,820 --> 00:08:32,900 through our experiments, is that we have a much better 164 00:08:32,900 --> 00:08:35,760 understanding of what we should tell people to do 165 00:08:35,760 --> 00:08:37,500 when they get stuck in a rip. 166 00:08:37,500 --> 00:08:39,060 This understanding has come through 167 00:08:39,060 --> 00:08:41,310 repeated experiments that required Rob 168 00:08:41,310 --> 00:08:44,120 and his research team to swim in different rip currents, 169 00:08:44,120 --> 00:08:45,980 with GPS attached to them. 170 00:08:45,980 --> 00:08:48,530 And to compare the results back to the data collected 171 00:08:48,530 --> 00:08:50,470 from the GPS drifters. 172 00:08:50,470 --> 00:08:53,223 This training exercise explains how this is done. 173 00:08:54,590 --> 00:08:57,620 We've got the beach here, this is the rip, 174 00:08:57,620 --> 00:08:59,280 essentially going like that. 175 00:08:59,280 --> 00:09:00,940 We're all gonna walk in together, 176 00:09:00,940 --> 00:09:03,300 to about that spot there, 177 00:09:03,300 --> 00:09:05,820 somebody's gonna swim parallel that way, 178 00:09:05,820 --> 00:09:08,400 somebody's gonna swim parallel that way, 179 00:09:08,400 --> 00:09:10,020 somebody's just gonna float, 180 00:09:10,020 --> 00:09:12,110 and somebody's gonna swim against the rip, 181 00:09:12,110 --> 00:09:13,103 back to the beach. 182 00:09:16,930 --> 00:09:20,040 Typically, rip currents are about 10 to 50 meters wide, 183 00:09:20,040 --> 00:09:23,380 and they can flow anywhere from 50 to 100 meters offshore, 184 00:09:23,380 --> 00:09:26,110 normally, but we've measured rip currents 185 00:09:26,110 --> 00:09:28,253 that have flown 400 meters offshore. 186 00:09:29,770 --> 00:09:32,210 It's never a good idea to actually try and swim against 187 00:09:32,210 --> 00:09:33,570 the flow of a rip current. 188 00:09:33,570 --> 00:09:35,980 In most cases, these rip currents are faster 189 00:09:35,980 --> 00:09:38,400 than most people can actually swim, so if you try 190 00:09:38,400 --> 00:09:40,500 swimming against that, you're just not gonna make 191 00:09:40,500 --> 00:09:42,160 any progress, whatsoever. 192 00:09:42,160 --> 00:09:44,160 We've also seen in our experiments that rips 193 00:09:44,160 --> 00:09:46,253 can pulse or accelerate in flow. 194 00:09:47,170 --> 00:09:50,780 Swimming parallel to escape a rip can often work. 195 00:09:50,780 --> 00:09:51,850 In many of our experiments, 196 00:09:51,850 --> 00:09:53,850 there was a really high success rate 197 00:09:53,850 --> 00:09:55,520 of getting out of the rip. 198 00:09:55,520 --> 00:09:57,200 But it didn't always work. 199 00:09:57,200 --> 00:09:59,720 And the reason for that is not all rip currents 200 00:09:59,720 --> 00:10:03,100 flow straight, and a lot of rip currents are these 201 00:10:03,100 --> 00:10:07,090 rotating eddies, that eddy flow will take you around 202 00:10:07,090 --> 00:10:09,940 in the shallow water, where you can likely stand up, 203 00:10:09,940 --> 00:10:11,370 and the waves are breaking, 204 00:10:11,370 --> 00:10:13,470 and you can use those breaking waves 205 00:10:13,470 --> 00:10:15,900 to get back to the beach and back to safety. 206 00:10:15,900 --> 00:10:18,060 The problem is that the average time 207 00:10:18,060 --> 00:10:21,590 for a rip current to recirculate you back into shallow water 208 00:10:21,590 --> 00:10:23,130 can be on the order of a couple of minutes 209 00:10:23,130 --> 00:10:24,560 to up to 10 minutes. 210 00:10:24,560 --> 00:10:27,780 The other option to escape a rip is just to stay afloat. 211 00:10:27,780 --> 00:10:30,390 And that makes sense, because you're conserving energy, 212 00:10:30,390 --> 00:10:32,930 and you can still put your hand up to signal for help. 213 00:10:32,930 --> 00:10:35,000 The problem is that if you stay afloat 214 00:10:35,000 --> 00:10:37,450 in a rip current that actually flows well beyond 215 00:10:37,450 --> 00:10:40,210 the surf zone, you're gonna get stuck out there, 216 00:10:40,210 --> 00:10:41,710 and you only have two options. 217 00:10:41,710 --> 00:10:44,010 One is that you're gonna get rescued, 218 00:10:44,010 --> 00:10:47,330 or you've got a long swim one way along the beach, 219 00:10:47,330 --> 00:10:48,730 and then back in. 220 00:10:48,730 --> 00:10:50,003 And that's a long swim. 221 00:10:53,090 --> 00:10:55,420 Rob's research has revealed that there's no 222 00:10:55,420 --> 00:10:58,040 single escape strategy that's guaranteed to get you 223 00:10:58,040 --> 00:10:59,090 out of a rip current. 224 00:10:59,970 --> 00:11:02,980 Instead, you have options based on the conditions 225 00:11:02,980 --> 00:11:04,443 and the behavior of the rip. 226 00:11:08,020 --> 00:11:10,710 The one factor that we have total control over 227 00:11:10,710 --> 00:11:15,049 may in fact be the key to our survival in any rip encounter. 228 00:11:15,049 --> 00:11:16,950 It's really panic that's the biggest killer 229 00:11:16,950 --> 00:11:19,370 when it comes to rips; rips don't drown you, 230 00:11:19,370 --> 00:11:21,440 they don't pull you under, but panic, 231 00:11:21,440 --> 00:11:22,833 panicking will drown you. 232 00:11:24,840 --> 00:11:27,560 Panicking sets off a chemical chain reaction. 233 00:11:27,560 --> 00:11:30,110 The nervous system floods the body with adrenaline. 234 00:11:31,810 --> 00:11:34,910 Fatigue is taking over, as the swimmer scrambles 235 00:11:34,910 --> 00:11:36,970 to stay above the water's surface. 236 00:11:36,970 --> 00:11:39,610 Each intense effort leads to greater amounts 237 00:11:39,610 --> 00:11:42,230 of lactic acid flooding the body. 238 00:11:42,230 --> 00:11:43,853 Causing muscular shutdown. 239 00:11:46,690 --> 00:11:50,093 In less than one minute, a life can be lost. 240 00:11:56,380 --> 00:11:58,550 The golden rule is to never attempt 241 00:11:58,550 --> 00:12:00,500 to swim against the current. 242 00:12:00,500 --> 00:12:03,750 Remember to stay calm and focus on floating. 243 00:12:03,750 --> 00:12:07,370 Just go with the current and raise your hand for help. 244 00:12:07,370 --> 00:12:09,280 And if you see someone struggling, 245 00:12:09,280 --> 00:12:12,250 always try to throw them a flotation device first, 246 00:12:12,250 --> 00:12:14,270 before entering the water. 247 00:12:14,270 --> 00:12:16,053 Otherwise, you both might drown. 248 00:12:17,795 --> 00:12:20,160 (dramatic music) 249 00:12:20,160 --> 00:12:22,916 Nearly all rip current tragedies could be avoided, 250 00:12:22,916 --> 00:12:25,560 if people didn't place themselves in harm's way 251 00:12:25,560 --> 00:12:26,393 to begin with. 252 00:12:27,490 --> 00:12:30,670 Complacency, coupled with a lack of skills to identify 253 00:12:30,670 --> 00:12:33,560 rip currents remains a critical beach safety issue 254 00:12:33,560 --> 00:12:36,510 for people choosing to swim outside the lifeguard areas, 255 00:12:36,510 --> 00:12:38,823 or on un-patrolled beaches.