https://neal.fun/deep-sea/

very cool interactive scroll-down website about the ocean

WOW!!!
Thanks for sharing that.

Amazing stuff. It talked about the whales making a dive up to 15 times a day. How long would it take a human to come up with decompression stops from that depth? How do the whales do it so quickly?

quote:

Originally posted by ffips:
Amazing stuff. It talked about the whales making a dive up to 15 times a day. How long would it take a human to come up with decompression stops from that depth? How do the whales do it so quickly?

Because whales are holding their breaths. They aren't using scuba tanks. They don't need to decompress. Or am I mistaken about that?

Scuba tanks rely on compressed air to give oxygen to a diver. This means that as pressure increases (one atmosphere every 33 feet) the volume of air in a tank also is compressed. So to 1/2 its volume at 33 feet.

So what you say!

At 33 feet, that means that the diver is taking in, effectively twice the amount of oxygen at 33 feet than she's getting at the surface.

Again, so what?

Well, starting at about 130 feet or so you are going to start running an experiment on yourself to see where you are going to suffer from oxygen toxicity. That magic number will be somewhere around 132 feet (where you are now effectively taking into your body 100% oxygen) to 330 feet (where every known human is going to go into convulsions and probably die (especially if needing a regulator in your mouth to breath) if only on compressed air).

This does NOT include the issue with the bends. As you are breathing that oxygen, your body is being slammed with nitrogen that effectively is going to turn you into a soda bottle. As you come up slow, that nitrogen (like the carbon dioxide in a soda bottle) will come out of solution in your body and will either slowly do it, allowing you to surface happy, or fast allowing you to surface into an unfun world of pain.

Whales/dolphins/seals/birds take a big breath and hold it. Their lungs collapse into a tiny, tiny thing as they evolved to do as the whale (etc.) goes down and down. To the point that if a breath hold human diver is doing it (again they are running an experiment to see where exactly on the bell curve they are as their lungs are compressed beyond to point of design) any human would die.

Appreciate the knowledge.

Question for Loswsmith:

Don't competitive free divers descend more than 400 feet?

That was pretty darn neat.

Thanks

quote:

Originally posted by V-Tail:
Question for Loswsmith:

Don't competitive free divers descend more than 400 feet?

Yes but the difference is they are not breathing any gas in at depth. They are holding their breath. All the issues Loswsmith describe come from taking a breath at depth. If you don't increase the air in your lung/body you don't have any of the issues a diver has.

Cool. Thanks!

quote:

Originally posted by Loswsmith:
Scuba tanks rely on compressed air to give oxygen to a diver. This means that as pressure increases (one atmosphere every 33 feet) the volume of air in a tank also is compressed. So to 1/2 its volume at 33 feet.

Regardless of the pressure on the outside of a scuba tank, the volume of any gas inside the tank will not change. Unless of course the tank itself is compressed, or collapsed.

quote:

Originally posted by V-Tail:
Question for Loswsmith:

Don't competitive free divers descend more than 400 feet?

Just once...................

I came up too fast and got the bendables

I used to routinely go beyond 4 minutes freediving, but never for depth. Too much can go wrong going for depth, but taking this approach meant never felt the need for scuba qualification.

He forgot to add what depth Osama Bin Laden's body was at.

Amazing
Never knew an elephant seal could dive that deep.
Thanks for sharing

quote:

Originally posted by Yellow Jacket:
Regardless of the pressure on the outside of a scuba tank, the volume of any gas inside the tank will not change....

Correct, but, the volume of gas required to fill your lungs changes as depth increases. A full breath at 33' you wont notice any change in pressure/volume of the cylinder, same breath at 300' you could actually see the needle move on the gauge.

that was really cool there. Had no idea penguins could dive to depths like that. Even ended up looking up and reading about some of the creatures I had never heard of.

Wow is right. That was an impressive display of the capability of life. Amazing. Thanks for sharing!

Showed this to my family yesterday and they loved it. They had no idea these creatures existed or that the ocean was so deep.

I do my best to teach when possible and this was a good opportunity.

Tony.