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B Excessive pressure underwater question -- Feeling my legs squeezed by my waders in a stream...

  1. Aug 2, 2017 #1
    Hi guys! I have question regarding vacuum and underwater pressure if anyone here could help me out with it. I'm not really a physics person (my math skills suck too much, lol), but I do find it very interesting.

    I recently bought some breathable stockingfoot fly fishing waders and whenever I go into waist deep water with them, the material that the waders are made from as well as the neoprene booties compress from the water pressure very tightly onto my legs and feet. If I am just wading without the waders on, the water pressure feels very minimal, but with the waders on it feels like they are literally crushing my legs and feet. Very uncomfortable.

    Underwater you can't pull the wader material away from your legs like it's sucked in really tight. There is this thing called suit-squeeze that happens to divers who wear drysuits. They have to inject forced air into the suit to prevent the water pressure from squeezing their body and causing injury. I think this is very similar if not identical to what is happening with my waders underwater, but I'm not 100% sure.

    When the water pressure forces the air out of the waders or out of the suit does it in effect create a partial vacuum? Other people are trying to tell me it's not creating any vacuum, but it sure feels like vacuum pressure to me so I figured I'd ask here. I guess it's similar to how some people would put meat or veggies in a plastic bag and then place it under water to press all the air out before freezing. A type of "vacuum" sealed packaging I guess. Does this process of removing all the air underwater actually create vacuum pressure or is there something else going on here?

    Last edited by a moderator: Aug 2, 2017
  2. jcsd
  3. Aug 2, 2017 #2


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    I am guessing here because I do not have experience with the feeling that you report.

    The inward pressure on the outside of your legs will be the same with waders or without. So it cannot be that. However, with the material in the waders pressed right up against your leg, you will feel a transverse force any time you try to move. This might well feel uncomfortable and could be interpreted as "pressure". By contrast, a pair of trousers that you wear to work is free to slide up and down your leg as you walk. And wading bare-legged, the water would also exert no transverse force.

    Edit: After having undergone hip replacement surgery earlier this year, I can testify that compression dressings get freaking painful after a while.
    Last edited: Aug 2, 2017
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