5 ms·

Very nicely done, technically. And the marketing message is both true and useful: Swimming at sea is surprisingly hard, and life jackets make a huge difference.

by ekidd 12y ago

Very nicely done, technically. And the marketing message is both true and useful: Swimming at sea is surprisingly hard, and life jackets make a huge difference. I was once a very strong swimmer, and back then, I tried swimming 60 feet to shore in water with choppy, 6-inch waves. I wound up repeatedly inhaling water and choking. To combat this, I tried to keep my head high above the water, which was exhausting. After 30 feet, it was clear I was in real trouble, so I called to the rowboat shadowing me 5 feet away and they towed me to shore. Similarly, cold water will shut me down frighteningly fast—even with a wetsuit and lifejacket, I've been stunned into near immobility after less than a minute of swimming. And I'm somebody who grew up swimming in the Gulf of Maine, which can be frigid (because Cape Cod deflects the warmer Gulf Stream eastward). The actual risk here is cold shock, not hypothermia—rapid vasoconstriction in your limbs will flood your core with blood, causing your heart to work much harder to maintain circulation. It's incredibly draining. A life-jacket will keep your head above water with minimal exertion. This means that (a) you keep breathing and (b) you remain visible to rescuers. It turns survival from an incredibly strenuous and terrifying athletic event into largely passive floating.

dbbolton 12y ago
The peripheral vasoconstriction is part of a reflex known as the mammalian dive reflex in which your heart actually slows down, rather than work harder, as soon as your face touches cold water. Muscle cramping is a direct result in the decrease in cardiac output. https://en.wikipedia.org/wiki/Mammalian_diving_reflex https://en.wikipedia.org/wiki/Mammalian_diving_reflex
- shiggerino 12y ago
  Another thing to note about mammalian diving reflex is that the nasal cavity is especially susceptible to triggering it. Which is why it's important to hold ones nose when jumping in the water to abandon ship, regardless of how silly it may look. And at this point you don't need a life jacket, you need an immersion suit.
puzzlingcaptcha 12y ago
Life jacket is good, but in higher seas one of the main problems (assuming the crew remaining on board is actually competent) is visibility - consider investing into something like a dan buoy https://www.youtube.com/watch?v=BMGWk6s9G4k https://www.youtube.com/watch?v=BMGWk6s9G4k
- nradov 12y ago
  Better visibility is helpful but even that doesn't do much in rough conditions or at night. Many of us scuba divers now carry Nautilus radios which include a GPS receiver and 2-way VHF marine radio with distress beacon. I bring mine whenever I go out on the ocean, even when I'm not diving. http://www.nautiluslifeline.com/nautilus_lifeline http://www.nautiluslifeline.com/nautilus_lifeline
  - shiggerino 12y ago
    DSC (digital selective calling), which that radio uses to transmit distress signals with coordinates, is an excellent but sadly under-used technology. Everyone should be equipped with it and be familiar with all the menus and options on their transceivers, and regularly test that the equipment is working by making routine calls. The problem with DSC is that the transceivers are really badly designed and downright user-hostile. The receiver usually gets a loud horn going of in their ears which only trains a reflex to reach for the silence button. It's pretty much only used for tests, and before anyone dares initiate a DSC call they call the receiving ship in advance the old-fashioned way, or they will get yelled at. When the whole point of DSC is that you merely enter the recipient's MMSI number, open a channel and just speak, without cluttering up channel 16 which is should be left for distress traffic only. Think Uhura in Star Trek. This is a huge risk to safety of life at sea that the industry urgently needs to deal with. But yes, do carry the equipment and do use it in an emergency, because it does work and it frees up yours and your rescuers' workload to worry about more important things than trying to get your coordinates across by voice. I would also suggest getting a SART and an EPIRB. A SART is a radar beacon, which shows up as a distinctive pattern on surrounding ships' radar displays, and requires no special receiving equipment. An EPIRB is a beacon that is locatable by satellite, so that's the fastest and most reliable way to get the attention of a rescue control centre. These three technologies are part of the GMDSS (Global Maritime Distress and Safety System), which means commercial ships and emergency services are by law required to carry and use equipment to receive their signals.
Tuna-Fish 12y ago
> Similarly, cold water will shut me down frighteningly fast—even with a wetsuit and lifejacket, I've been stunned into near immobility after less than a minute of swimming. As someone who routinely goes swimming in a hole cut in ice with the water temperature typically around 1C, this sounds weird. I suppose it's a reaction you can teach your body to not have?
- mjlee 12y ago
  You can acclimatise to it but cold shock response is a very real thing. The first minute is the most important - you're lucky to survive long enough to die of hypothermia.
  - Tuna-Fish 12y ago
    The typical way people swim among ice is to first just dip yourself, get up from the water, hang out for like a minute, then go back in there. I wonder if this has something to do with it?
- kiiski 12y ago
  You don't get your face/head wet when ice swimming, I suppose?
  - Tuna-Fish 12y ago
    I generally don't dip my ears below the surface because ear infections are a risk, but I certainly get my face wet.
nbardy 12y ago
I'm very surprised to hear how hard it was for you to swim in light chop. I grew up surfing and you paddle with your head up so you are used to craning your neck and stroke at an angle down. When I finally starting doing some swimming in a pool I was amazed at how much easier it was to swim. Especially maintaining momentum. I also swim quite frequently without a board in open water when the waves are small, but there is still light chop and although it's surprising how slow it is I've never felt it was particularly difficult. Interesting how things work much differently transitioning the other way. Also when you talk about wetsuit, it sounds like you haven't used a good/thick wetsuit. Or maybe this was a while ago. Wetsuit technology has been pushed really far in the last 5 years. Dry suits have always been good thanks to the military, but sports wetsuits have really progressed a lot with the explosion of the surf industry. I stay in the water easily twice as long now than I did with my first suit I bought five years ago.
- ekidd 12y ago
  The chop thing was really surprising to me at the time, which is part of my point. I'd been swimming in the Gulf of Maine for years without any problem, and I didn't anticipate trouble. But the wind was really screwy and I kept aspirating salt water, and things turned bad much faster than I expected. I do agree, however, that better rough water swimming technique would have helped. My wetsuit is good but relatively light, and I was testing it under controlled circumstances. I'm a river kayaker, a sport which involves working hard in warm air before suddenly getting plunged into a cold river. It's the sudden transition that can cause cold shock: http://en.wikipedia.org/wiki/Cold_shock_response http://en.wikipedia.org/wiki/Cold_shock_response http://www.seakayak.ws/kayak/kayak.nsf/0/9ABAF7D7992B820585256A640054C71F http://www.seakayak.ws/kayak/kayak.nsf/0/9ABAF7D7992B8205852... The second link mentions cases of sea kayakers who were dead within seconds of overturning. Cold shock happens much faster than hypothermia. Fortunately, both of my misadventures happened under controlled circumstances with a backup plan. But in both cases, I was surprised and scared at how quickly I lost my ability to swim. The interactive video we're discussing actually captures the feeling pretty well.
  - Swizec 12y ago
    I've never felt it was particularly difficult to swim in the sea. I wonder why that is. Two reasons come to mind: 1) Since I was a kid, sea-side vacations in the summer were common-place to the point that I actually learned how to swim in the sea. I still remember how surprised I was at the difficulty of swimming in a pool where you are much less buoyant. No salt in the water and all that. And 2) Maybe I just haven't swam in choppy enough water. But I do remember that when waves are a certain height above your head, having a surfboard at hand suddenly makes life so much easier. Although even then I didn't feel a particular propensity to inhaling water. edit: 3) I learned several techniques for swimming in place and resting when you're tired. If push comes to shove, you can also just lay on the water pretty much indefinitely. This one doesn't work if the water is too choppy though. 4) I probably haven't swam in a super cold sea yet. Think the coldest I've done without a wetsuit was Monterey Bay last summer where I managed to skinny dip for some half an hour or so.
mrbonner 12y ago
| Swimming at sea is surprisingly hard, and life jackets make a huge difference. I can confirm this. When I was about 16 - 17 yo (and I was very fit at the time) we went sailing with 2 of my friends on a 8 ft sailboat in Nha Trang, Vietmam. About a mile out from the shoreline the boat capsized. We were very foolish not bringing any life-jackets. After 20 - 25 minutes trying to swim back to the shore in the afternoon's high tide and high wind one of my friend had a leg cramp. We were so lucky that we had an Igloo watercooler to tether to and relied on the wind to bring us ashore. My friend died 6 months later from cancer in California. The other guy clung to the capsized boat and also relied the wind to bring him ashore. He ended up 5 miles from the original spot we launched the boat.
- 6t6t6 12y ago
  For anyone reading this. First rule: If the boat didn't sink, never abandon it. It is relatively easy for a rescue helicopter to find a capsized boat. Not so easy to spot someone swimming. Also, you can probably manage to stay out of the water on top of the hull. If the boat sank, stay all together next to the biggest piece of floating debris. Source: sailing license exam. :P
frobozz 12y ago
> A life-jacket will keep your head above water with minimal exertion. With no exertion, depending on conditions. Lifejackets should be able to support an unconscious casualty.

by ekidd 12y ago

dbbolton 12y ago

The peripheral vasoconstriction is part of a reflex known as the mammalian dive reflex in which your heart actually slows down, rather than work harder, as soon as your face touches cold water. Muscle cramping is a direct result in the decrease in cardiac output. https://en.wikipedia.org/wiki/Mammalian_diving_reflex https://en.wikipedia.org/wiki/Mammalian_diving_reflex

shiggerino 12y ago
Another thing to note about mammalian diving reflex is that the nasal cavity is especially susceptible to triggering it. Which is why it's important to hold ones nose when jumping in the water to abandon ship, regardless of how silly it may look. And at this point you don't need a life jacket, you need an immersion suit.

puzzlingcaptcha 12y ago

Life jacket is good, but in higher seas one of the main problems (assuming the crew remaining on board is actually competent) is visibility - consider investing into something like a dan buoy https://www.youtube.com/watch?v=BMGWk6s9G4k https://www.youtube.com/watch?v=BMGWk6s9G4k

nradov 12y ago
Better visibility is helpful but even that doesn't do much in rough conditions or at night. Many of us scuba divers now carry Nautilus radios which include a GPS receiver and 2-way VHF marine radio with distress beacon. I bring mine whenever I go out on the ocean, even when I'm not diving. http://www.nautiluslifeline.com/nautilus_lifeline http://www.nautiluslifeline.com/nautilus_lifeline
- shiggerino 12y ago
  DSC (digital selective calling), which that radio uses to transmit distress signals with coordinates, is an excellent but sadly under-used technology. Everyone should be equipped with it and be familiar with all the menus and options on their transceivers, and regularly test that the equipment is working by making routine calls. The problem with DSC is that the transceivers are really badly designed and downright user-hostile. The receiver usually gets a loud horn going of in their ears which only trains a reflex to reach for the silence button. It's pretty much only used for tests, and before anyone dares initiate a DSC call they call the receiving ship in advance the old-fashioned way, or they will get yelled at. When the whole point of DSC is that you merely enter the recipient's MMSI number, open a channel and just speak, without cluttering up channel 16 which is should be left for distress traffic only. Think Uhura in Star Trek. This is a huge risk to safety of life at sea that the industry urgently needs to deal with. But yes, do carry the equipment and do use it in an emergency, because it does work and it frees up yours and your rescuers' workload to worry about more important things than trying to get your coordinates across by voice. I would also suggest getting a SART and an EPIRB. A SART is a radar beacon, which shows up as a distinctive pattern on surrounding ships' radar displays, and requires no special receiving equipment. An EPIRB is a beacon that is locatable by satellite, so that's the fastest and most reliable way to get the attention of a rescue control centre. These three technologies are part of the GMDSS (Global Maritime Distress and Safety System), which means commercial ships and emergency services are by law required to carry and use equipment to receive their signals.

Tuna-Fish 12y ago

> Similarly, cold water will shut me down frighteningly fast—even with a wetsuit and lifejacket, I've been stunned into near immobility after less than a minute of swimming. As someone who routinely goes swimming in a hole cut in ice with the water temperature typically around 1C, this sounds weird. I suppose it's a reaction you can teach your body to not have?

mjlee 12y ago
You can acclimatise to it but cold shock response is a very real thing. The first minute is the most important - you're lucky to survive long enough to die of hypothermia.
- Tuna-Fish 12y ago
  The typical way people swim among ice is to first just dip yourself, get up from the water, hang out for like a minute, then go back in there. I wonder if this has something to do with it?
kiiski 12y ago
You don't get your face/head wet when ice swimming, I suppose?
- Tuna-Fish 12y ago
  I generally don't dip my ears below the surface because ear infections are a risk, but I certainly get my face wet.

nbardy 12y ago

I'm very surprised to hear how hard it was for you to swim in light chop. I grew up surfing and you paddle with your head up so you are used to craning your neck and stroke at an angle down. When I finally starting doing some swimming in a pool I was amazed at how much easier it was to swim. Especially maintaining momentum. I also swim quite frequently without a board in open water when the waves are small, but there is still light chop and although it's surprising how slow it is I've never felt it was particularly difficult. Interesting how things work much differently transitioning the other way. Also when you talk about wetsuit, it sounds like you haven't used a good/thick wetsuit. Or maybe this was a while ago. Wetsuit technology has been pushed really far in the last 5 years. Dry suits have always been good thanks to the military, but sports wetsuits have really progressed a lot with the explosion of the surf industry. I stay in the water easily twice as long now than I did with my first suit I bought five years ago.

ekidd 12y ago
The chop thing was really surprising to me at the time, which is part of my point. I'd been swimming in the Gulf of Maine for years without any problem, and I didn't anticipate trouble. But the wind was really screwy and I kept aspirating salt water, and things turned bad much faster than I expected. I do agree, however, that better rough water swimming technique would have helped. My wetsuit is good but relatively light, and I was testing it under controlled circumstances. I'm a river kayaker, a sport which involves working hard in warm air before suddenly getting plunged into a cold river. It's the sudden transition that can cause cold shock: http://en.wikipedia.org/wiki/Cold_shock_response http://en.wikipedia.org/wiki/Cold_shock_response http://www.seakayak.ws/kayak/kayak.nsf/0/9ABAF7D7992B820585256A640054C71F http://www.seakayak.ws/kayak/kayak.nsf/0/9ABAF7D7992B8205852... The second link mentions cases of sea kayakers who were dead within seconds of overturning. Cold shock happens much faster than hypothermia. Fortunately, both of my misadventures happened under controlled circumstances with a backup plan. But in both cases, I was surprised and scared at how quickly I lost my ability to swim. The interactive video we're discussing actually captures the feeling pretty well.
- Swizec 12y ago
  I've never felt it was particularly difficult to swim in the sea. I wonder why that is. Two reasons come to mind: 1) Since I was a kid, sea-side vacations in the summer were common-place to the point that I actually learned how to swim in the sea. I still remember how surprised I was at the difficulty of swimming in a pool where you are much less buoyant. No salt in the water and all that. And 2) Maybe I just haven't swam in choppy enough water. But I do remember that when waves are a certain height above your head, having a surfboard at hand suddenly makes life so much easier. Although even then I didn't feel a particular propensity to inhaling water. edit: 3) I learned several techniques for swimming in place and resting when you're tired. If push comes to shove, you can also just lay on the water pretty much indefinitely. This one doesn't work if the water is too choppy though. 4) I probably haven't swam in a super cold sea yet. Think the coldest I've done without a wetsuit was Monterey Bay last summer where I managed to skinny dip for some half an hour or so.

mrbonner 12y ago

| Swimming at sea is surprisingly hard, and life jackets make a huge difference. I can confirm this. When I was about 16 - 17 yo (and I was very fit at the time) we went sailing with 2 of my friends on a 8 ft sailboat in Nha Trang, Vietmam. About a mile out from the shoreline the boat capsized. We were very foolish not bringing any life-jackets. After 20 - 25 minutes trying to swim back to the shore in the afternoon's high tide and high wind one of my friend had a leg cramp. We were so lucky that we had an Igloo watercooler to tether to and relied on the wind to bring us ashore. My friend died 6 months later from cancer in California. The other guy clung to the capsized boat and also relied the wind to bring him ashore. He ended up 5 miles from the original spot we launched the boat.

6t6t6 12y ago
For anyone reading this. First rule: If the boat didn't sink, never abandon it. It is relatively easy for a rescue helicopter to find a capsized boat. Not so easy to spot someone swimming. Also, you can probably manage to stay out of the water on top of the hull. If the boat sank, stay all together next to the biggest piece of floating debris. Source: sailing license exam. :P

frobozz 12y ago

> A life-jacket will keep your head above water with minimal exertion. With no exertion, depending on conditions. Lifejackets should be able to support an unconscious casualty.