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Comment by srean | Hacker News Reader

Sperm whales are incredibly interesting animals. Amongst their multiple records is their ability to dive deep, fast and long.

They are the deepest diving warm blooded animal, they go close to 25 times deeper than their other equally famous and endangered cousin the blue whale. To give an idea of how deep they dive, here is an infographic http://i.imgur.com/ESp2j.jpg The jpg needs to be magnified to get the perspective. From the biological point view what is interesting is not only how they manage to hold their breath for so long but also how they manage to avoid/survive the bends (decompression sickness).

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A quick addition to the awesomeness of sperm whales: part of the reason they dive so deep/long is to hunt giant squid. While a sperm whale vs. giant squid battle has never been observed, there are multiple counts of sperm whales with scars that are from squids and in some cases almost certainly from giant squid.

They find giant squid beaks inside sperm whale stomachs too.

Yes, that's apparently what causes them to secrete ambergris.

Interestingly this, combined with scars is really the only way we know how big giant squid can get. The largest that has been actually observed or caught is really quite small in comparison to the sizes indicated from sperm whale data.

I should add that this topic made me take a second look at giant squid data (what can i say, i think they are really interesting creatures). It does appear that large giant squid have been found dead but never seen alive or caught. Those seen in a well documented manor or caught have been around 25ft in length max, while the expected maximum size is around 60ft with the largest dead specimen being about 59ft long, although that was in 1878 so i don't consider it overly reliable data.

Add to the list the story where a large sperm whale managed to sink a whaleship that was attacking multiple of its kin [1] (story which later inspired Moby-Dick).

[1] http://en.wikipedia.org/wiki/Essex_(whaleship)#Whale_attack

The book "In the Heart of the Sea: The Tragedy of the Whaleship Essex" by Nathaniel Philbrick is great, BTW.

My dive-master friend has told me that the bends isn't an issue if you're holding your breath. The bends is a result of the air mixture that you're breathing with a SCUBA.

This is why freedivers can dive down to 100meters, and then come back up quickly without dieing.

This is not true. DCS has been found in cases of free-divers who perform repeated deep dives. The primary gas that causes DCS is nitrogen, which exists in large quantities in the air you are breathing now. The reason you don't often see DCS in free divers is that it takes time for the high-pressure nitrogen to dissolve in the blood and enter tissue.

On the other hand, think about it. With a SCUBA tank, you are taking many breaths under high pressure. With a single free-dive, you only take one breath. With many free-dives, you take many breaths. Is it surprising that repeated deep free-dives cause DCS?

So, it's not a problem if you dive once and go home. But it is a problem if you dive again, and again, and again.

Makes sense.

Depends on how deep you dive and the time you spend down there. for instance, people that attempt world records in freediving might need some decompression time after the dive.

My dad was a doctor on a small island, for a year. The islanders dived for sponges and pearls. They couldn't afford a decompression chamber, so if someone got DCS (after freediving too long) they dropped them off the side of the jetty with an old diving helmet, and a friend to keep them company, and pumped air down to them as they gradually re-ascended. Apparently it worked OK.

I've also read when free-divers are down in such high pressure the plasma of their blood is squeezed out and fills their sinuses. In a way it helps protect them since the large open areas are now filled with fluid.

They do dive deep, but there are various animals that I find more surprising. For example, Wikipedia claims 500m+ for emperor pinguins and 600m for elephant seals.

Also, IIRC, it is fairly hard to get the bends without using scuba gear (not that that says much, but I do not think free divers consider it a grey risk)

What is the gibberish between 31.000 and 36.000 feet supposed to mean? Just an oversight?

It's the invented script from the Cthulhu mythos by the gothic horror writer HP Lovecraft. Cthulhu slept at the bottom of the sea, before being awakened by man or something. I don't know, I haven't read it. That's what the big scary monster thing to the left of the script is.

It's a big part of geek culture, it made its way into D&D, and via that into everything else.

Good infographic, but it misses the actual deepest dive by a warm blooded animal at over 35,000 feet: http://en.wikipedia.org/wiki/Bathyscaphe_Trieste

*Freedive

So that nobody wastes their time. The wikipedia link is to a submarine that made the deepest dive with humans aboard.

I think most people understood "the deepest dive" to mean unaided / freedive.

Is that Cthulhu [1] hiding at the bottom?

[1] http://www.southparkstudios.com/guide/episodes/s14e13-coon-v...

http://en.wikipedia.org/wiki/Cthulu

That's a very interesting infographic. Is the pixel at 15,000ft supposed to be a scale representation of the Alvin?

And, Cthulu? WTF?

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