WEBVTT 00:00:00.000 --> 00:00:03.040 So imagine for a second that you're working this 00:00:03.040 --> 00:00:05.740 really high -stakes job where basically your 00:00:05.740 --> 00:00:08.179 schedule completely dictates your biology. Right, 00:00:08.259 --> 00:00:10.580 like your entire life. Exactly. I mean, your 00:00:10.580 --> 00:00:14.419 meals, your sleep, your downtime, all of it is 00:00:14.419 --> 00:00:16.420 just relentlessly governed by a spreadsheet. 00:00:18.300 --> 00:00:21.280 And there's absolutely no such thing as clocking 00:00:21.280 --> 00:00:23.359 out and going home. You are permanently at the 00:00:23.359 --> 00:00:25.579 office. Which is a terrifying thought for most 00:00:25.579 --> 00:00:28.010 people, I think. Oh, for sure. And... To make 00:00:28.010 --> 00:00:31.609 it worse, if someone, anyone, really makes a 00:00:31.609 --> 00:00:33.890 simple mistake in that schedule, or if someone 00:00:33.890 --> 00:00:35.969 just gets too tired and loses focus, the entire 00:00:35.969 --> 00:00:38.810 office could literally sink. Literally sink to 00:00:38.810 --> 00:00:41.270 the bottom of the ocean. Right. So welcome to 00:00:41.270 --> 00:00:43.630 another custom deep dive. This one is tailored 00:00:43.630 --> 00:00:45.689 specifically for you, the learner, because today 00:00:45.689 --> 00:00:49.390 our mission is to decode the extreme, highly 00:00:49.390 --> 00:00:51.570 mathematical time management systems used at 00:00:51.570 --> 00:00:54.109 sea. The systems that keep these massive vessels 00:00:54.109 --> 00:00:57.649 running 24 -7. Yeah, without the crew just completely 00:00:57.649 --> 00:00:59.570 collapsing from exhaustion, we're diving into 00:00:59.570 --> 00:01:02.149 a Wikipedia article on watchkeeping to strip 00:01:02.149 --> 00:01:04.549 down both the ancient and the modern art of, 00:01:04.549 --> 00:01:07.640 well, staying awake at sea. And it is, I mean, 00:01:07.760 --> 00:01:09.959 it's just the perfect subject to dissect because 00:01:09.959 --> 00:01:12.599 watchkeeping or watch standing, it isn't just 00:01:12.599 --> 00:01:14.900 about assigning shift work. It's the fundamental 00:01:14.900 --> 00:01:16.980 heartbeat of maritime survival. Heartbeat, yeah. 00:01:17.000 --> 00:01:20.120 It's how a ship breathes, how it moves, and most 00:01:20.120 --> 00:01:22.659 importantly, how it stays safe in an environment 00:01:22.659 --> 00:01:25.180 that is honestly constantly trying to destroy 00:01:25.180 --> 00:01:28.000 it. OK, let's unpack this a bit because to really 00:01:28.000 --> 00:01:30.060 understand the intense math of this scheduling, 00:01:30.640 --> 00:01:34.439 we first need to understand the beast we're actually 00:01:34.439 --> 00:01:37.599 trying to tame here. Right. A ship is essentially 00:01:37.599 --> 00:01:41.459 a 24 -hour living organism, like a floating city. 00:01:41.659 --> 00:01:44.099 And in this city, the brain and the heart can 00:01:44.099 --> 00:01:46.480 never ever be allowed to sleep. Precisely. You 00:01:46.480 --> 00:01:49.379 simply cannot turn the lights off. So watchkeeping 00:01:49.379 --> 00:01:52.340 is this continuous assignment of sailors to highly 00:01:52.340 --> 00:01:55.319 specific critical roles. We're talking about 00:01:55.319 --> 00:01:57.519 roles that are absolutely essential for safe 00:01:57.519 --> 00:02:01.400 operation and rapid emergency response. So if 00:02:01.400 --> 00:02:03.519 you look up in the brain of the ship, the bridge, 00:02:03.640 --> 00:02:07.299 you have the navigational watch. the sheer physical 00:02:07.299 --> 00:02:09.860 and mental focus required for these bridge rolls 00:02:09.860 --> 00:02:12.900 is just, I mean, it's what makes the scheduling 00:02:12.900 --> 00:02:15.020 so incredibly difficult, right? Oh, absolutely. 00:02:15.120 --> 00:02:18.000 Because you have a lookout peering into pitch 00:02:18.000 --> 00:02:21.819 black darkness or freezing rain, just trying 00:02:21.819 --> 00:02:24.639 to spot unlit fishing boats out on the water. 00:02:24.879 --> 00:02:27.539 Yeah, that takes a massive toll on the eyes and 00:02:27.539 --> 00:02:30.020 the brain. And then you have the helmsman, who 00:02:30.020 --> 00:02:33.639 isn't just passively steering. They are. physically 00:02:33.639 --> 00:02:36.639 holding a multi -thousand ton steel building 00:02:36.639 --> 00:02:39.120 on a precise compass degree. While the ocean 00:02:39.120 --> 00:02:41.360 is actively trying to push it off course. Exactly. 00:02:41.879 --> 00:02:44.340 And overseeing all of them is the deck officer 00:02:44.340 --> 00:02:47.039 who literally holds the ultimate responsibility 00:02:47.039 --> 00:02:49.740 for the safe navigation of the entire ship. And 00:02:49.740 --> 00:02:51.539 then if you go deep down into the heart of the 00:02:51.539 --> 00:02:53.900 ship, the engine room, the stakes are equally 00:02:53.900 --> 00:02:57.000 high. If not higher, really. Oh wow, really? 00:02:57.120 --> 00:02:58.879 Yeah, because you have the engineering officer 00:02:58.879 --> 00:03:00.919 of the watch making sure all this massive running 00:03:00.919 --> 00:03:04.120 machinery stays within incredibly strict tolerances. 00:03:04.479 --> 00:03:06.500 You've got a damage control watch, an electrical 00:03:06.500 --> 00:03:08.419 systems watch, and of course the boiler watch. 00:03:08.719 --> 00:03:11.419 Right, and a boiler is essentially just a massive 00:03:11.419 --> 00:03:14.340 control bomb of pressurized steam. That's a very 00:03:14.340 --> 00:03:16.639 good way to put it. So if the person on the boiler 00:03:16.639 --> 00:03:19.560 watch zones out and the water level drops too 00:03:19.560 --> 00:03:22.669 low, the boiler can literally explode. And they're 00:03:22.669 --> 00:03:25.889 doing this while staring at pressure gauges in, 00:03:26.210 --> 00:03:30.349 what, 110 degree heat for hours. Yes, it is grueling. 00:03:30.409 --> 00:03:33.069 Plus, on top of navigation and engineering, you 00:03:33.069 --> 00:03:35.689 have security watches guarding against piracy. 00:03:35.870 --> 00:03:38.830 You have communications watches manning the radios. 00:03:39.449 --> 00:03:42.129 And on naval vessels, you've got a combat watch 00:03:42.129 --> 00:03:44.849 with a tactical action officer who is just constantly 00:03:44.849 --> 00:03:47.689 scanning for threats. Every single one of these 00:03:47.689 --> 00:03:51.370 roles requires absolute unbroken vigilance. Because... 00:03:51.400 --> 00:03:53.960 A momentary lapse in concentration doesn't just 00:03:53.960 --> 00:03:55.979 mean like, oh, I missed a slack message. No, 00:03:55.979 --> 00:03:59.120 it means a collision, or a fire, or running the 00:03:59.120 --> 00:04:01.400 ship aground. Which brings up this massive logistical 00:04:01.400 --> 00:04:03.919 problem. Because frankly, if I stare at a spreadsheet 00:04:03.919 --> 00:04:06.219 for four hours, my brain completely turns to 00:04:06.219 --> 00:04:08.060 mush. Right, your cognitive function just drops. 00:04:08.460 --> 00:04:11.500 Yeah. So with so many incredibly distinct, high 00:04:11.500 --> 00:04:14.860 -focus roles, how do you mathematically ensure 00:04:14.860 --> 00:04:17.579 someone is always awake and perfectly alert without 00:04:17.579 --> 00:04:20.529 entirely burning out the crew? I mean, navies 00:04:20.529 --> 00:04:24.149 couldn't exactly just adopt a land -based nine 00:04:24.149 --> 00:04:27.189 -to -five schedule. No, they couldn't. And what's 00:04:27.189 --> 00:04:29.089 fascinating here is that the solution required 00:04:29.089 --> 00:04:32.610 a completely bespoke concept of time. Navies 00:04:32.610 --> 00:04:34.990 were forced to invent these highly unorthodox 00:04:34.990 --> 00:04:37.449 schedules. Effectively hacking the clock. Exactly. 00:04:37.589 --> 00:04:39.310 Hacking the clock to keep the ship alive and 00:04:39.310 --> 00:04:42.759 the crew functional. And the oldest and arguably 00:04:42.759 --> 00:04:45.000 the cleverest mathematical solution actually 00:04:45.000 --> 00:04:47.800 comes from the traditional systems from the days 00:04:47.800 --> 00:04:50.980 of sail. Right. Originating in 19th century sailing 00:04:50.980 --> 00:04:54.560 ships and heavily popularized by the Royal Navy. 00:04:55.060 --> 00:04:57.779 So this foundational system took the crew, whose 00:04:57.779 --> 00:04:59.899 work obviously had to be done around the clock, 00:05:00.319 --> 00:05:02.500 and divided them into two simple divisions, right? 00:05:02.660 --> 00:05:04.959 Port and starboard. Yes, port and starboard. 00:05:04.959 --> 00:05:06.720 Now let's just do the basic math on that. You 00:05:06.720 --> 00:05:08.720 have a 24 hour day. If you just divide it by 00:05:08.720 --> 00:05:11.279 two teams, everyone works. 12 hours on and then 00:05:11.279 --> 00:05:13.480 12 hours off. Which sounds sort of like a standard 00:05:13.480 --> 00:05:16.620 hospital shift or something. It does, but standing 00:05:16.620 --> 00:05:19.480 in the freezing rain, hauling heavy rigging for 00:05:19.480 --> 00:05:22.439 12 straight hours is physically impossible. Oh, 00:05:22.439 --> 00:05:25.519 right. Humans can't do that. No. So they slice 00:05:25.519 --> 00:05:28.459 the 24 -hour day into smaller, more manageable 00:05:28.459 --> 00:05:31.459 periods. Traditionally, these were four -hour 00:05:31.459 --> 00:05:34.420 blocks. But wait, if you just use four -hour 00:05:34.420 --> 00:05:37.199 blocks, you run into this brutal mathematical 00:05:37.199 --> 00:05:41.959 wall. Because 24 divided by 4 is 6, and 6 is 00:05:41.959 --> 00:05:44.279 an even number. Exactly, you see the problem. 00:05:44.420 --> 00:05:46.660 Yeah, if you have two teams working an even number 00:05:46.660 --> 00:05:49.139 of shifts, they will work the exact same shifts 00:05:49.139 --> 00:05:51.540 every single day. So if your team gets stuck 00:05:51.540 --> 00:05:54.519 with that miserable midnight to 4 a .m. graveyard 00:05:54.519 --> 00:05:56.079 shift. What they traditionally call the middle 00:05:56.079 --> 00:05:57.800 watch. Right, the middle watch. You would work 00:05:57.800 --> 00:06:00.180 it on Monday, Tuesday, Wednesday forever. Like 00:06:00.180 --> 00:06:02.000 you would literally never see the sun. And that 00:06:02.000 --> 00:06:04.939 is a very quick recipe for mutiny, not to mention 00:06:04.939 --> 00:06:08.019 profound physical decline. Right. So to solve 00:06:08.019 --> 00:06:10.639 this, the traditional system features this brilliant 00:06:10.639 --> 00:06:13.699 structural modification. You have five four -hour 00:06:13.699 --> 00:06:17.360 periods and then crucially two two -hour periods. 00:06:17.759 --> 00:06:19.500 And here's where it gets really interesting. 00:06:19.939 --> 00:06:21.980 They took one of those standard four -hour blocks 00:06:21.980 --> 00:06:23.860 and just chopped it right in half. Yes, they 00:06:23.860 --> 00:06:26.480 did. And these shorter blocks happened in the 00:06:26.480 --> 00:06:29.350 late afternoon and early evening. So the first 00:06:29.350 --> 00:06:33.870 dog watch runs from 1600 to 1800 hours so 4 p 00:06:33.870 --> 00:06:37.209 .m. to 6 p .m. and the second or last dog watch 00:06:37.209 --> 00:06:40.550 runs from 1800 to 20 hundred hours or 6 p .m. 00:06:40.569 --> 00:06:43.009 to 8 p .m. And by splitting that one shift into 00:06:43.009 --> 00:06:45.610 two smaller ones, you change the total number 00:06:45.610 --> 00:06:48.389 of shifts in a day from six to seven. Which is 00:06:48.389 --> 00:06:50.550 an odd number. Right. Seven is an odd number. 00:06:50.889 --> 00:06:53.170 And because seven doesn't divide evenly between 00:06:53.170 --> 00:06:56.069 two teams, the rotation naturally shifts. It's 00:06:56.069 --> 00:06:58.170 like a slipping gear. It acts like a leap year 00:06:58.170 --> 00:07:00.740 for your daily schedule. It's this intentional, 00:07:01.100 --> 00:07:04.759 ingenious, mathematical glitch. Because of that 00:07:04.759 --> 00:07:07.180 odd number of shifts, if you worked the crushing 00:07:07.180 --> 00:07:10.019 middle watch on Monday, the gear slips, and the 00:07:10.019 --> 00:07:12.360 other team is forced to work it on Tuesday. Exactly. 00:07:12.439 --> 00:07:14.279 It completely solves the rotation problem. But 00:07:14.279 --> 00:07:17.100 I have to ask, why place those tiny two -hour 00:07:17.100 --> 00:07:19.879 shifts right at 4 p .m. and 6 p .m.? Why not 00:07:19.879 --> 00:07:22.000 the morning? Well, that comes down to purely 00:07:22.000 --> 00:07:25.759 practical logistics. 4 p .m. to 8 p .m. is dinner 00:07:25.759 --> 00:07:29.680 time. Oh, of course. Food. Always food. Having 00:07:29.680 --> 00:07:32.139 shorter two -hour shifts right in the middle 00:07:32.139 --> 00:07:35.040 of the evening allowed the entire crew, so both 00:07:35.040 --> 00:07:37.040 the oncoming watch and the off -going watch, 00:07:37.459 --> 00:07:41.100 to be fed a hot meal in short order right before 00:07:41.100 --> 00:07:43.860 the long dark night shifts began. Wow, that is 00:07:43.860 --> 00:07:47.089 so elegant. And as ships got larger and, you 00:07:47.089 --> 00:07:49.589 know, crews expanded, they didn't just use this 00:07:49.589 --> 00:07:51.470 for two divisions. They adapted it for three 00:07:51.470 --> 00:07:54.350 sections to give sailors even more time off duty. 00:07:54.850 --> 00:07:57.089 Yes, a three -section watch becomes much more 00:07:57.089 --> 00:07:59.449 common later on. And the naming conventions they 00:07:59.449 --> 00:08:01.269 use for these three -section watches are just 00:08:01.269 --> 00:08:03.350 incredible to me. Depending on the ship, they 00:08:03.350 --> 00:08:06.250 might name the sections foremast, mainmast, and 00:08:06.250 --> 00:08:08.689 mizzen, referring to the ship's actual sails. 00:08:08.730 --> 00:08:11.569 A very traditional nautical approach. Yeah, or... 00:08:11.579 --> 00:08:13.519 My personal favorite. They would just use the 00:08:13.519 --> 00:08:15.779 delightfully arbitrary tomato white and blue. 00:08:16.100 --> 00:08:18.540 Which is fantastic. But, you know, if we connect 00:08:18.540 --> 00:08:21.040 this back to the bigger picture, the psychological 00:08:21.040 --> 00:08:23.199 brilliance of the dog watch really cannot be 00:08:23.199 --> 00:08:25.560 overstated. How so? Well, rotating the burden 00:08:25.560 --> 00:08:28.199 of the worst shifts is absolutely essential for 00:08:28.199 --> 00:08:31.920 morale. In a highly isolated, stressful environment, 00:08:32.559 --> 00:08:35.460 perceived fairness is what maintains unit cohesion. 00:08:35.679 --> 00:08:37.179 Right. If I feel like I'm getting screwed over 00:08:37.179 --> 00:08:38.580 every night while you sleep, I'm going to hate 00:08:38.580 --> 00:08:41.399 you. Exactly. Shared hardship is the glue that 00:08:41.399 --> 00:08:43.620 keeps a crew from turning on each other. OK. 00:08:43.840 --> 00:08:46.940 So the dog watch brilliantly solved the issue 00:08:46.940 --> 00:08:50.809 of fairness on the surface. But it completely 00:08:50.809 --> 00:08:53.929 relied on a normal human routine, right? Like 00:08:53.929 --> 00:08:57.750 meal times, sunsets, the natural rhythm of day 00:08:57.750 --> 00:09:00.470 turning into night. Yes, it was tied to the sun. 00:09:00.690 --> 00:09:03.269 So what happens when you completely remove the 00:09:03.269 --> 00:09:04.889 sun? I mean, when you look at early submarines, 00:09:05.450 --> 00:09:07.370 this traditional system completely falls apart, 00:09:07.509 --> 00:09:09.769 doesn't it? It does, because submarines push 00:09:09.769 --> 00:09:12.850 human biology to the absolute brink. They operate 00:09:12.850 --> 00:09:14.970 in a completely artificial environment. Right, 00:09:15.070 --> 00:09:16.669 there is no day or night down there. None at 00:09:16.669 --> 00:09:19.049 all. Because the crew is cut off from sunlight 00:09:19.049 --> 00:09:21.730 and the natural passage of days, Navy started 00:09:21.730 --> 00:09:24.289 experimenting with time in ways that, frankly, 00:09:24.610 --> 00:09:27.889 seem entirely alien to us on land. Alien is exactly 00:09:27.889 --> 00:09:30.009 the right word. In the sources we looked at, 00:09:30.289 --> 00:09:32.850 there's a system called the five and dime, and 00:09:32.850 --> 00:09:35.340 they literally split the day into four. five 00:09:35.340 --> 00:09:37.820 -hour watches, and then one four -hour watch 00:09:37.820 --> 00:09:40.840 to round out the 24 hours. Which is disorienting 00:09:40.840 --> 00:09:43.259 enough. Right. But that is just child's play 00:09:43.259 --> 00:09:45.600 compared to the historic United States submarine 00:09:45.600 --> 00:09:48.740 system. Oh, yes. The historic U .S. submarine 00:09:48.740 --> 00:09:51.480 schedule is just a perfect example of prioritizing 00:09:51.480 --> 00:09:54.120 operational efficiency over fundamental human 00:09:54.120 --> 00:09:57.960 biology. It's wild. For nearly 45 years, up until 00:09:57.960 --> 00:10:01.139 around 2015, U .S. submariners did not live on 00:10:01.139 --> 00:10:04.460 a 24 -hour day. They lived on an 18 -hour day. 00:10:04.639 --> 00:10:06.820 Wait, okay. I really need to push back on the 00:10:06.820 --> 00:10:09.419 biological reality of this. An 18 -hour loop? 00:10:09.580 --> 00:10:13.539 An 18 -hour loop. But human beings are hardwired 00:10:13.539 --> 00:10:16.620 by millions of years of evolution to a 24 -hour 00:10:16.620 --> 00:10:19.740 circadian rhythm. You're telling me that highly 00:10:19.740 --> 00:10:22.340 trained personnel who are operating nuclear reactors 00:10:22.340 --> 00:10:24.899 and handling arm torpedoes deep underwater were 00:10:24.899 --> 00:10:27.039 actively forced to fight their own biological 00:10:27.039 --> 00:10:30.460 clocks for months on end? Yes, they were. Wouldn't 00:10:30.460 --> 00:10:33.500 constantly fighting that cycle make them incredibly 00:10:33.500 --> 00:10:36.980 prone to disastrous mistakes? It absolutely caused 00:10:36.980 --> 00:10:39.980 severe fatigue. Living on an 18 -hour cycle is 00:10:39.980 --> 00:10:42.779 essentially like flying from New York to Paris 00:10:42.779 --> 00:10:46.440 every single day, forever. Your body expects 00:10:46.440 --> 00:10:48.820 it to be the middle of the night, but the ship's 00:10:48.820 --> 00:10:51.240 clock says it's time to run a complex tactical 00:10:51.240 --> 00:10:54.259 drill. So the crew is divided into three sections. 00:10:55.059 --> 00:10:57.639 You would spend six hours on watch, followed 00:10:57.639 --> 00:11:01.539 by 12 hours off watch. Six plus twelve equals 00:11:01.539 --> 00:11:04.340 your 18 -hour day. Okay, let's walk through that 00:11:04.340 --> 00:11:06.940 because it hurts my head Yeah, day one you wake 00:11:06.940 --> 00:11:09.440 up at midnight for your shift right day two your 00:11:09.440 --> 00:11:12.639 morning starts at 6 p .m. Day three you are waking 00:11:12.639 --> 00:11:15.690 up at noon your body would never ever acclimate 00:11:15.690 --> 00:11:17.950 to that. Never. And those 12 hours off, they 00:11:17.950 --> 00:11:19.570 weren't just for sleeping, right? Not at all. 00:11:19.789 --> 00:11:21.870 The first six hours off watch were dedicated 00:11:21.870 --> 00:11:24.509 to grueling maintenance, cleaning the ship, working 00:11:24.509 --> 00:11:27.529 on qualifications, and if you were lucky, maybe 00:11:27.529 --> 00:11:29.269 a tiny sliver of entertainment. You're still 00:11:29.269 --> 00:11:33.169 working. Yes. Only the final six hours were explicitly 00:11:33.169 --> 00:11:36.120 reserved for sleep. And because the cycle was 00:11:36.120 --> 00:11:38.960 a relentless 18 hours, it meant that on certain 00:11:38.960 --> 00:11:41.440 calendar days, a single section would actually 00:11:41.440 --> 00:11:45.059 work two full six -hour watches within a single 00:11:45.059 --> 00:11:47.679 24 -hour period. So you're chronically sleep 00:11:47.679 --> 00:11:50.980 deprived, constantly jet lagged, and performing 00:11:50.980 --> 00:11:53.919 highly technical engineering tasks. It's no wonder 00:11:53.919 --> 00:11:55.960 they eventually realized this was completely 00:11:55.960 --> 00:11:57.820 unsustainable. Exactly. This raises an important 00:11:57.820 --> 00:12:00.340 question, right? At what point does pushing human 00:12:00.340 --> 00:12:02.980 endurance actually become a liability to the 00:12:02.980 --> 00:12:04.769 mission itself? You're not making them tougher. 00:12:05.110 --> 00:12:07.190 You're making them dangerous. Precisely. The 00:12:07.190 --> 00:12:09.590 modern US submarine force finally reckoned with 00:12:09.590 --> 00:12:12.850 the hard data on cognitive decline. They realized 00:12:12.850 --> 00:12:15.769 that a sleep deprived sonar operator is a dangerous 00:12:15.769 --> 00:12:18.929 sonar operator. Yeah, obviously. So they recently 00:12:18.929 --> 00:12:22.330 shifted back to a 24 hour routine. Now it's typically 00:12:22.330 --> 00:12:25.649 eight hours on watch and 16 hours off. Which 00:12:25.649 --> 00:12:27.570 actually aligns with human biology. Thankfully, 00:12:27.750 --> 00:12:30.139 yes. And looking at the mechanics of how they 00:12:30.139 --> 00:12:32.399 handle the handovers for these modern eight -hour 00:12:32.399 --> 00:12:36.379 shifts, it is incredibly precise. The watch turnovers 00:12:36.379 --> 00:12:39.480 happen at the bottom of the hour, so 2330, or 00:12:39.480 --> 00:12:42.980 530, and 1530. And that specific timing is vital 00:12:42.980 --> 00:12:45.100 for space management. You have to remember, a 00:12:45.100 --> 00:12:47.100 submarine has very limited mess hall seating. 00:12:47.220 --> 00:12:51.159 Oh, right. It's a tiny tube. Exactly. By shifting 00:12:51.159 --> 00:12:53.620 the turnover to the bottom of the hour, the oncoming 00:12:53.620 --> 00:12:56.000 crew uses the first 30 minutes of the hour to 00:12:56.000 --> 00:12:58.720 eat their meal and get to their stations. Then 00:12:58.720 --> 00:13:01.000 the off -going crew is relieved and they use 00:13:01.000 --> 00:13:03.840 the second 30 minutes to eat. It creates the 00:13:03.840 --> 00:13:06.899 seamless flow of bodies in a very tight metal 00:13:06.899 --> 00:13:10.549 tube. That's brilliant. We also see navies experimenting 00:13:10.549 --> 00:13:13.049 with the one and two watch system Sometimes called 00:13:13.049 --> 00:13:16.149 sevens and fives which aims to give sailors longer 00:13:16.149 --> 00:13:19.750 unbroken sleeping periods Yes Prioritizing actual 00:13:19.750 --> 00:13:22.289 rest and crucially it features something culturally 00:13:22.289 --> 00:13:25.690 beloved in the Navy mid -rats, or midnight rations, 00:13:26.129 --> 00:13:28.009 served at the midnight turnover just to keep 00:13:28.009 --> 00:13:30.730 morale up. Food is one of the only comforts available 00:13:30.730 --> 00:13:32.649 out there, so its scheduling is honestly just 00:13:32.649 --> 00:13:35.309 as important as the watch itself. The sources 00:13:35.309 --> 00:13:38.470 also detail the Swedish system variations, which 00:13:38.470 --> 00:13:41.370 use unequal schedule blocks. Like what? Like 00:13:41.370 --> 00:13:43.470 six hours on, six hours off, four on, four off, 00:13:43.509 --> 00:13:46.049 and four off. Oh, I see. So instead of equal 00:13:46.049 --> 00:13:48.950 repetitive blocks, varying the shift lengths 00:13:48.950 --> 00:13:52.480 breaks up the brutal monotony. Like, a six -hour 00:13:52.480 --> 00:13:55.320 block allows for one solid chunk of unbroken 00:13:55.320 --> 00:13:58.059 deep sleep, while the shorter four -hour blocks 00:13:58.059 --> 00:14:00.320 handle the active periods of the day. Exactly. 00:14:00.399 --> 00:14:02.480 It's a constant mathematical puzzle trying to 00:14:02.480 --> 00:14:05.259 cheat fatigue. But here's the massive contrast. 00:14:05.820 --> 00:14:08.679 While naval forces are constantly inventing complex 00:14:08.679 --> 00:14:11.440 rotations in these bizarre time loops to optimize 00:14:11.440 --> 00:14:14.379 fairness and rest, the commercial side of seafaring 00:14:14.379 --> 00:14:16.360 takes the exact opposite approach. Yes, they 00:14:16.360 --> 00:14:18.610 really do. If naval watches are all about shared 00:14:18.610 --> 00:14:21.309 hardship and complex rotations, merchant ships 00:14:21.309 --> 00:14:24.190 are about strict hierarchy and ironclad consistency. 00:14:24.389 --> 00:14:26.809 No slipping gears here. None at all. The standard 00:14:26.809 --> 00:14:28.809 merchant system is incredibly straightforward. 00:14:28.909 --> 00:14:32.230 It consists entirely of six periods of four consecutive 00:14:32.230 --> 00:14:36.309 hours, and it never ever rotates. So if you are 00:14:36.309 --> 00:14:38.769 assigned to the four to eight watch, you always 00:14:38.769 --> 00:14:41.669 work 4 a .m. to 8 a .m. and 4 p .m. to 8 p .m. 00:14:41.669 --> 00:14:44.110 Every single day. Every single day for months. 00:14:44.350 --> 00:14:47.370 You never get a dog watch to mix things up. But 00:14:47.370 --> 00:14:50.950 wait, isn't doing the exact same fragmented sleep 00:14:50.950 --> 00:14:53.470 schedule every single day just as exhausting 00:14:53.470 --> 00:14:55.350 as the submarine jet lag we just talked about? 00:14:55.730 --> 00:14:58.470 Well. I mean, you are perpetually waking up in 00:14:58.470 --> 00:15:01.230 the middle of the night. It is undeniably physically 00:15:01.230 --> 00:15:03.309 taxing. You are never getting eight hours of 00:15:03.309 --> 00:15:06.889 straight sleep. However, there is immense psychological 00:15:06.889 --> 00:15:09.649 comfort and extreme predictability. OK, I get 00:15:09.649 --> 00:15:12.159 that. In a highly commercial environment, you 00:15:12.159 --> 00:15:14.899 want to lower the cognitive load. On a merchant 00:15:14.899 --> 00:15:17.220 vessel, you never have to consult a spreadsheet 00:15:17.220 --> 00:15:19.799 to wonder what time you work tomorrow. You know 00:15:19.799 --> 00:15:21.639 exactly when you will sleep, when you'll eat, 00:15:21.860 --> 00:15:24.240 and when you'll work. That ironclad routine just 00:15:24.240 --> 00:15:26.700 becomes second nature. Exactly. And the strategic 00:15:26.700 --> 00:15:29.960 placement of who works which hours is entirely 00:15:29.960 --> 00:15:32.679 based on hierarchy. and risk management. For 00:15:32.679 --> 00:15:35.399 instance, the least experienced watchkeepers, 00:15:35.759 --> 00:15:38.279 like the junior officers, are intentionally assigned 00:15:38.279 --> 00:15:41.659 to the 8 to 12 block, so 8 a .m. to noon and 00:15:41.659 --> 00:15:44.379 8 p .m. to midnight. Because that is when the 00:15:44.379 --> 00:15:46.519 captain and the senior officers are most likely 00:15:46.519 --> 00:15:48.960 to be awake, walking around the ship, and readily 00:15:48.960 --> 00:15:52.710 available to help. Right. Absolutely do not want 00:15:52.710 --> 00:15:55.970 your least experienced crew member making critical 00:15:55.970 --> 00:15:58.889 collision avoidance decisions at 3 a .m. when 00:15:58.889 --> 00:16:01.690 the captain is deep in REM sleep. Precisely. 00:16:01.850 --> 00:16:04.450 It's risk mitigation. And the mechanics behind 00:16:04.450 --> 00:16:07.070 the four to eight watch are even more specific. 00:16:07.809 --> 00:16:10.610 This blew my mind. Your John title literally 00:16:10.610 --> 00:16:12.830 dictates your time zone on the ship. It really 00:16:12.830 --> 00:16:15.169 does. On a standard five off the ship, the second 00:16:15.169 --> 00:16:17.730 mate who serves as the ship's dedicated navigator 00:16:17.730 --> 00:16:19.970 always takes the four to eight watch. And that 00:16:19.970 --> 00:16:22.409 is entirely driven by the physical mechanics 00:16:22.409 --> 00:16:24.809 of celestial navigation. OK, break that down 00:16:24.809 --> 00:16:27.450 for us. Well, to navigate using a sextant, you 00:16:27.450 --> 00:16:29.529 need to measure the angle between a specific 00:16:29.529 --> 00:16:32.720 star and the visible horizon. Right. And if you 00:16:32.720 --> 00:16:34.279 try to do that in the dead of night, you can 00:16:34.279 --> 00:16:36.980 see the stars perfectly. But the ocean is pitch 00:16:36.980 --> 00:16:39.539 black, so you have absolutely no horizon line 00:16:39.539 --> 00:16:41.980 to measure against. Exactly. And if you try to 00:16:41.980 --> 00:16:45.480 do it in broad daylight, you have a perfect sharp 00:16:45.480 --> 00:16:47.940 horizon, but the stars are completely washed 00:16:47.940 --> 00:16:50.220 out by the sun. So you're stuck. Unless you use 00:16:50.220 --> 00:16:53.799 nautical twilight. That brief 30 to 45 minute 00:16:53.799 --> 00:16:56.740 window at dawn and dusk when both the stars and 00:16:56.740 --> 00:16:59.460 the horizon are simultaneously visible. Oh, wow. 00:16:59.720 --> 00:17:02.480 Therefore, the navigator fundamentally must be 00:17:02.480 --> 00:17:05.500 awake and on the bridge during dawn and dusk. 00:17:05.640 --> 00:17:07.839 The four to eight watch covers both of those 00:17:07.839 --> 00:17:10.619 twilight periods perfectly. That makes perfect 00:17:10.619 --> 00:17:13.319 mechanical sense. And on a smaller four officer 00:17:13.319 --> 00:17:16.059 ship, the chief mate, who is essentially the 00:17:16.059 --> 00:17:18.660 executive officer, takes that four to eight watch. 00:17:18.779 --> 00:17:20.680 Because of their specific duties, right? Yeah. 00:17:20.809 --> 00:17:22.910 Because the chief mate is in charge of the deck 00:17:22.910 --> 00:17:25.349 GAN and all the physical ship maintenance. By 00:17:25.349 --> 00:17:27.990 working 4 a .m. to 8 a .m., they finish their 00:17:27.990 --> 00:17:30.750 watch just as the regular day shift begins. Right, 00:17:30.750 --> 00:17:33.930 at 0800. Right. They can assign painting, rust 00:17:33.930 --> 00:17:37.250 removal, and cargo work to the crew at 8 a .m., 00:17:37.250 --> 00:17:39.710 go get some sleep, and then wake up to inspect 00:17:39.710 --> 00:17:41.670 all that work before they go back on watch at 00:17:41.670 --> 00:17:44.470 4 p .m. So what does this all mean? It means 00:17:44.470 --> 00:17:47.869 every single hour is optimized for the commercial 00:17:47.869 --> 00:17:50.740 output of the vessel. The maritime world has 00:17:50.740 --> 00:17:54.259 spent centuries refining how to keep a 24 -7 00:17:54.259 --> 00:17:57.440 operation running safely. And looking at how 00:17:57.440 --> 00:18:01.079 ruthlessly efficient, yet physically demanding 00:18:01.079 --> 00:18:03.880 these systems are, it really connects back to 00:18:03.880 --> 00:18:08.059 the reality of modern life on land. How so? 24 00:18:08.059 --> 00:18:11.160 -7, always on, digital world. It can sometimes 00:18:11.160 --> 00:18:13.319 feel like we are all navigating a ship that never 00:18:13.319 --> 00:18:15.599 sleeps. Oh, absolutely. The burnout is real. 00:18:15.799 --> 00:18:18.099 We are constantly answering emails at all hours, 00:18:18.539 --> 00:18:21.000 fighting our own natural circadian rhythms, just 00:18:21.000 --> 00:18:23.579 trying to balance endless productivity with basic 00:18:23.579 --> 00:18:26.019 human rest. And we are experiencing only a fraction 00:18:26.019 --> 00:18:28.039 of the cognitive load that sailors have managed 00:18:28.039 --> 00:18:29.940 for hundreds of years. I mean, they've learned 00:18:29.940 --> 00:18:32.059 the hard way what happens when you ignore human 00:18:32.059 --> 00:18:34.980 limits. You get catastrophic failures. Exactly. 00:18:35.339 --> 00:18:37.920 The shift from the 18 -hour submarine loop back 00:18:37.920 --> 00:18:41.359 to a 24 -hour day is proof that you just cannot 00:18:41.359 --> 00:18:45.240 out -engineer biology forever. Maybe we need 00:18:45.240 --> 00:18:47.440 to borrow some of these maritime strategies for 00:18:47.440 --> 00:18:49.819 our own lives Like that idea like to break up 00:18:49.819 --> 00:18:52.079 the monotony of our work weeks. Maybe we all 00:18:52.079 --> 00:18:55.240 need to schedule a personal dog watch, you know 00:18:55.240 --> 00:18:58.640 a Deliberate planned glitch in our routine like 00:18:58.640 --> 00:19:01.960 an odd hour break or an unusual evening activity 00:19:01.960 --> 00:19:04.240 Just to keep us from burning out on the exact 00:19:04.240 --> 00:19:06.460 same repeating schedule That's a great takeaway 00:19:06.460 --> 00:19:09.519 or at the absolute minimum We should definitely 00:19:09.519 --> 00:19:13.019 start adopting mid rats to keep our morale high 00:19:13.019 --> 00:19:15.829 when we're burn the midnight oil. I think introducing 00:19:15.829 --> 00:19:17.710 midnight rations to the corporate world would 00:19:17.710 --> 00:19:20.289 be highly, highly effective. Right. Pizza at 00:19:20.289 --> 00:19:22.089 midnight solves a lot of problems. It really 00:19:22.089 --> 00:19:24.569 does. But, you know, before we finish, there 00:19:24.569 --> 00:19:27.150 is one final detail from our sources that completely 00:19:27.150 --> 00:19:29.269 changes how you visualize this entire system. 00:19:29.589 --> 00:19:32.809 Oh. We've talked about these schedules as spreadsheets, 00:19:32.930 --> 00:19:36.250 right? as numbers on a digital clock. But historically, 00:19:36.609 --> 00:19:39.029 and actually still in many vessels today, time 00:19:39.029 --> 00:19:41.690 is tracked by the ship's bell. Yes, the acoustic 00:19:41.690 --> 00:19:44.609 countdown. I love this part. Right. A ship's 00:19:44.609 --> 00:19:48.630 bell doesn't chime the actual hour, like a grandfather 00:19:48.630 --> 00:19:51.470 clock in your living room. Instead, the bell 00:19:51.470 --> 00:19:54.809 is inextricably linked to the watch system itself. 00:19:55.009 --> 00:19:57.759 How does it work? It strikes up to eight times 00:19:57.759 --> 00:20:00.220 one strike for every half hour of a standard 00:20:00.220 --> 00:20:02.720 four -hour watch. So at the first half hour, 00:20:02.819 --> 00:20:05.839 one bell at the hour, two bells. At an hour and 00:20:05.839 --> 00:20:07.720 a half, three bells, all the way up to eight 00:20:07.720 --> 00:20:10.279 bells, marking the absolute end of the four -hour 00:20:10.279 --> 00:20:13.480 watch. And crucially, it chimes in distinct pairs, 00:20:13.920 --> 00:20:16.019 making it incredibly easy to count in the dark 00:20:16.019 --> 00:20:18.480 or like through the howling noise of a storm, 00:20:18.599 --> 00:20:21.539 ding, ding, pow, ding, ding. So just imagine 00:20:21.539 --> 00:20:23.480 you are standing on the bridge of that ship in 00:20:23.480 --> 00:20:25.900 the freezing rain. Yeah. You aren't staring at 00:20:25.900 --> 00:20:28.819 a digital clock on a screen watching tiny numbers 00:20:28.819 --> 00:20:31.500 tick by in silence. No, you're listening. Your 00:20:31.500 --> 00:20:34.500 progress, your literal survival through that 00:20:34.500 --> 00:20:38.160 shift, is measured by a massive auditory countdown. 00:20:39.119 --> 00:20:41.160 Imagine how your psychological perception of 00:20:41.160 --> 00:20:43.299 a grueling workday would change if time was this 00:20:43.299 --> 00:20:45.180 echoing physical presence ringing out across 00:20:45.180 --> 00:20:47.460 your workspace. Letting you know half hour by 00:20:47.460 --> 00:20:50.880 half hour. that your relief is coming. It transforms 00:20:50.880 --> 00:20:53.799 the abstract concept of a shift schedule into 00:20:53.799 --> 00:20:57.140 a shared physical reality. Everyone on the ship, 00:20:57.319 --> 00:20:59.059 whether they are deep in the engine room or high 00:20:59.059 --> 00:21:01.380 on the bridge, here's the exact same heartbeat. 00:21:01.619 --> 00:21:03.819 A heartbeat that keeps the floating city alive. 00:21:04.849 --> 00:21:07.549 Wow. Well, that is all the time we have for today's 00:21:07.549 --> 00:21:09.750 journey into the extreme time management of the 00:21:09.750 --> 00:21:12.390 seas. Thank you for exploring the mechanics of 00:21:12.390 --> 00:21:14.690 maritime watch standing with us. We hope you 00:21:14.690 --> 00:21:16.529 find a way to build a little piece of that protective 00:21:16.529 --> 00:21:19.049 rhythm into your own schedule today. Until next 00:21:19.049 --> 00:21:19.930 time, keep diving.