Diving

secondcurve · 12-12-2005, 09:12 PM

This is a little off topic, but I just read a great dive book called Shadow Divers. It is about wreck divers working off the coast of New Jersey in the early ninetees trying to locate and then identify an old German U2 boat. The thing that got me thinking about Winnipesaukee is that thet were working in 200 to 230 foot waters, about the same depth as Winnipesaukee's deepest point. It was noted that these depths are considered extremely dangerous, especially when using pure oxygen. Have any of the divers on the forum read the book?

Mee-n-Mac · 12-13-2005, 04:26 AM

There was a PBS show on the same sub & dive(s). IIRC there were 2 deaths, father & son, on one of the dives. They did eventually ID the sub which had been thought to have been lost in another area. As far as deep dives go there was another show I saw recently where the divers were recovering gold from a WWII transport ship. They were working saturation dives in what I thought was deeper than an unprotected (not in a hardsuit) diver could go. I think they said 600' ?!??!??

Perhaps the divers here could comment on either/both ...

Senter Cove Guy · 12-13-2005, 01:48 PM

I read the book in Oct. 2004 and bought the DVD of the PBS show in 2005. Both are excellent. Three people lost their lives while diving the sub (U-869) and John Chatterton, who retrieved the evidence that ultimately identified the sub, almost lost his after executing a special maneuver to get himself deeper into the sub and getting temporarily pinned under some wreckage that fell on him.

I had a chance to talk with John Chatterton at the 2005 Boston Sea Rovers conference in March 2005. He, Richie Kohler (another U-869 diver) and Robert Kurson (the author of Shadow Divers), made a presentation at the conference.

The DVD has a lot of great underwater footage plus some graphical animations of the special maneuvers that Chatterton had to perform to get deep enough into the sub to get the evidence. It also contains a lot of WWII information about German submarine warfare planning and a visit by Richie and John to a former U-869 submariner still living in Germany and to a relative, living in the United States, of one of the submariner's who died when the sub went down.

Chatterton, Kohler and other U-869 divers used a trimix gas (oxygen, helium and nitrogen) when diving the sub. The helium took the place of some of the nitrogen that normally would have been in the mix which has the effect of reducing the absorption of Nitrogen into the blood thus reducing the chances of getting the bends. They might have breathed pure oxygen during their ascent from 235 feet while stopping at pre-determined decompression depth stops to allow Nitrogen to purge from their bloodstream. A 20-25 minute bottom time dive at 235 feet requires somewhere in the 1.5 - 2 hrs of decompression stops I believe.

Mink Islander · 12-13-2005, 02:03 PM

once they get to a safe depth where the partial pressure of oxygen based on whatever EAN mix they're using is 1.6 bar or less, right?

AttitudeAdjuster · 12-13-2005, 04:41 PM

Quote:

Originally Posted by Mink Islander

once they get to a safe depth where the partial pressure of oxygen based on whatever EAN mix they're using is 1.6 bar or less, right?

I believe you mean 1.6Po2. 100% oxygen has a Po2 of 1.6 @19.8 fsw.
they would not want to ascend from 235 on 100% that would be a deadly case of oxtox.

Senter Cove Guy · 12-13-2005, 06:00 PM

Quote:

Originally Posted by AttitudeAdjuster

I believe you mean 1.6Po2. 100% oxygen has a Po2 of 1.6 @19.8 fsw.
they would not want to ascend from 235 on 100% that would be a deadly case of oxtox.

I did not mean to infer that they would have been breathing 100% oxygen all the way up from 235 feet but that at some point in their decompression, they might do that to hasten the purge of nitrogen.

The DVD clearly shows that each diver began his dive with 4 tanks. Two in the standard position on their back and one on each side hanging from their buoyancy compensator.

The father and son team that died made deadly errors. Firstly, they couldn't afford to buy trimix so they dove using air. Secondly, the son got trapped inside the sub while the father was outside. He finally went in looking for his son, found and freed him but both exited the sub from a different point from where they went in and where they'd left their extra tanks. Nitrogen narcosis set in because they were breathing air vs. trimix and in a stressful situation and they couldn't find their extra tanks. Almost out of air, they surfaced without decompressing and both died of the bends.

Mee-n-Mac · 12-13-2005, 06:31 PM

I'm curious if the divers could settle an old question I have. Somewhere I recall reading or seeing some info that while decompression stops usually prevent the bends from occuring, it's not guaranteed. You can do everything "by the book" and still end up with bubbles where you don't want them ? Just curious ....

gtxrider · 12-13-2005, 11:19 PM

Can the experts help on this question? Can you get the bends coming up to fast in shallow water? We were told that by our diving instructor.

It also depends on the number of dives over a given time period.
Did you ever notice that I you when hear a diver speaking on those very deep dives their voices sound funny? The helium in the mix does that.

warren · 12-13-2005, 11:55 PM

its a great story,the owner of the dive shop in concord nh. rob dove the u-boat this summer and said it was a wonderfull dive. he said the vis was not very good until he hit about 150 feet and then the the whole sub came into view underneath him. cool huh, warren

Senter Cove Guy · 12-14-2005, 12:42 PM

Quote:

Originally Posted by gtxrider

Can the experts help on this question? Can you get the bends coming up to fast in shallow water? We were told that by our diving instructor.

Unlikely because the bends is related to the amount of nitrogen in the bloodstream. Diving depth and the related pressure that exists determines how much nitrogen is absorbed by the blood. So it's more a factor of how deep you dive and how long you are there that controls how much nitrogen is in your bloodstream.

However, the general rule is don't ascend any faster than 30 feet per minute and either obey your dive computer when it says STOP at calculated decompression stops or, if not using a computer, plan your dive and dive your plan.

One thing you don't want to do in any depth of water, when breathing compressed air, is hold your breath when ascending. A depth change of only 4 feet is enough to cause the compressed air in your lungs to expand and burst them which would be deadly.

Senter Cove Guy · 12-17-2005, 04:05 PM

If you liked reading Shadow Divers, then you might also like the following 2 books:

Deep Descent - A story about diving the Andrea Doria

Last Dive - The complete story of the lives of the father & son team that died diving the U-869.

Mee-n-Mac · 12-18-2005, 11:43 PM

Just to answer my own question as to how deep unprotected people could go ... I found that a few years ago somebody went to 1010 ft. Don't know the details but I guess the 600 ft I was wondering about (above) is indeed possible. Personally I think I'll leave the deeper than snorkel depths to an ROV.

Grant · 12-19-2005, 11:53 AM

Oddly enough, we routinely hear about people taking DCS hits after what most would consider relatively shallow, short dives. In fact, I believe the author of "The Last Dive" took a pretty nasty hit after a rather basic dive. Took him out of commission for quite some time. So, yes, you can follow the tables, use a super-conservative dive computer, hydrate like a fish, take prolonged safety stops, use Nitrox, tri-mix, stay shallow, ascend slower than the slowest bubble, wear a rabbit's foot, pray, and still get hit.

Today, in addition to the customary 3-5 minutes @ 15 ft. "safety stop," a lot of recreational divers are factoring in a short stop at a depth equal to 1/2 of their deepest point of the dive. Statistics suggest that this does indeed lessen the frequency of DCS. There are so many factors.

Richie Kohler, one of the two primaries in "Shadow Divers" lives a few miles from where I'm sitting right now. The Jersey dive community is very active around here, and all the local shops have affiliations with the boats up and down the shore. The Rouses, the father-son team that died diving the "U-Who," dove out of my local shop, and the younger Rouse worked there. Some of their artifacts from the Andrea Doria are on display in the shop.

Grant · 12-19-2005, 12:00 PM

Quote:

Originally Posted by Mee-n-Mac

Just to answer my own question as to how deep unprotected people could go ... I found that a few years ago somebody went to 1010 ft. Don't know the details but I guess the 600 ft I was wondering about (above) is indeed possible. Personally I think I'll leave the deeper than snorkel depths to an ROV.

The open circuit record is 1030 feet -- and that was a bounce dive. FWIW, "recreational" diving is considered to be anything to 130 ft, with anything deeper considered "deep diving." (Your mileage may vary.) Most basic certs (OW) set a limit at 60 ft. (unenforced, of course). Winnipesaukee is pretty worthless (extremely dark, murky, cold) below, say, 50-60 feet, and the 'best' diving in the Lake is probably in the 30-50 foot range.

The 600 you mentioned is indeed possible, and done fairly often, but that is a seriously deep technical dive, requiring special gases, prolonged decompression, and LOTS of training.

secondcurve · 12-19-2005, 10:18 PM

Grant & Senter Cove Guy:

Thanks for the info on diving. Have either of you had problems or close calls when diving? I know that you proably haven't gone as deep as the divers in Shadow Divers but none the less, it seems risky even in waters as tame as Lake Winnipesaukee. How deep have each of you gone down? How many dives have you each made. Finally, isn't diving in Winnipesaukee kind of boring? Thanks for any input. Senter Cove Guy, I think I'm going to take your recoomendation and pick up a copy of the Last Dive.

Thanks

Grant · 12-19-2005, 11:11 PM

Funny you should ask...

Actually, Senter Cove Guy and I live quite close to each other at the Lake, and dive together fairly often...when crappy weather and lack of air don't conspire against us...

As far as depth, I've only gone as deep as 120', but not in Winnipesaukee. As I mentioned above, most of the good diving in Winni is much shallower than that. My max to date in the Lake is probably '70 or so.

As for Winnipesaukee, it's FAR from boring. Lots of stuff to see. It's 70 square miles of puddle carved out by a glacier -- so the geologic formations alone are worth the price of admission. And the junk...don't get me started on the junk...and I'm but a newbie in this department. Page a forum member knows as Winnipesaukee Divers...he's a bona fide junkmeister general and a seriously seasoned diver. He's found all sorts of glorious refuse.

I'm just in it for the fun and to see another side of the Lake I've loved all my life. If I find some treasures and see some critters along the way, bonus. If you're interested in hitting some of the cooler spots in the Lake, jump on one of the charters with Dive Winnipesaukee out of Wolfeboro. There aren't too many dive shops on the planet with a boat parked right out back! Wonderful folks who are more than glad to show you the popular sites around the Lake.

Funny, at least two or three times a year, I have people approach me on the street in Wolfeboro, as I'm taking a cylinder to the shop, who ask me, "You actually dive in this lake? What on earth is there to see in there???" Kills me every time.

Senter Cover Guy (left) and yours fatly, er, I mean truly, on the surface this fall about 7 hours south of Winni...

SIKSUKR · 12-20-2005, 09:23 AM

How come Grant and SCG are diving behind a Super Wal-mart in their water treatment pond?Just kidding guys!!

Grant · 12-20-2005, 10:13 AM

Because they needed underwater "greeters," and because WalMart pays so well.

12-12-2005, 09:12 PM	#1
secondcurve Senior Member Join Date: Jan 2005 Posts: 2,120 Thanks: 1,333 Thanked 559 Times in 288 Posts	Diving This is a little off topic, but I just read a great dive book called Shadow Divers. It is about wreck divers working off the coast of New Jersey in the early ninetees trying to locate and then identify an old German U2 boat. The thing that got me thinking about Winnipesaukee is that thet were working in 200 to 230 foot waters, about the same depth as Winnipesaukee's deepest point. It was noted that these depths are considered extremely dangerous, especially when using pure oxygen. Have any of the divers on the forum read the book?

12-13-2005, 04:26 AM	#2
Mee-n-Mac Senior Member Join Date: Sep 2003 Posts: 1,943 Thanks: 23 Thanked 111 Times in 51 Posts	PBS show There was a PBS show on the same sub & dive(s). IIRC there were 2 deaths, father & son, on one of the dives. They did eventually ID the sub which had been thought to have been lost in another area. As far as deep dives go there was another show I saw recently where the divers were recovering gold from a WWII transport ship. They were working saturation dives in what I thought was deeper than an unprotected (not in a hardsuit) diver could go. I think they said 600' ?!??!?? Perhaps the divers here could comment on either/both ... __________________ Mee'n'Mac "Never attribute to malice that which can be explained by simple stupidity or ignorance. The latter are a lot more common than the former." - RAH Last edited by Mee-n-Mac; 12-13-2005 at 05:25 PM.

12-13-2005, 01:48 PM	#3
Senter Cove Guy Senior Member Join Date: Apr 2004 Posts: 604 Thanks: 298 Thanked 431 Times in 142 Posts	Book & PBS Show I read the book in Oct. 2004 and bought the DVD of the PBS show in 2005. Both are excellent. Three people lost their lives while diving the sub (U-869) and John Chatterton, who retrieved the evidence that ultimately identified the sub, almost lost his after executing a special maneuver to get himself deeper into the sub and getting temporarily pinned under some wreckage that fell on him. I had a chance to talk with John Chatterton at the 2005 Boston Sea Rovers conference in March 2005. He, Richie Kohler (another U-869 diver) and Robert Kurson (the author of Shadow Divers), made a presentation at the conference. The DVD has a lot of great underwater footage plus some graphical animations of the special maneuvers that Chatterton had to perform to get deep enough into the sub to get the evidence. It also contains a lot of WWII information about German submarine warfare planning and a visit by Richie and John to a former U-869 submariner still living in Germany and to a relative, living in the United States, of one of the submariner's who died when the sub went down. Chatterton, Kohler and other U-869 divers used a trimix gas (oxygen, helium and nitrogen) when diving the sub. The helium took the place of some of the nitrogen that normally would have been in the mix which has the effect of reducing the absorption of Nitrogen into the blood thus reducing the chances of getting the bends. They might have breathed pure oxygen during their ascent from 235 feet while stopping at pre-determined decompression depth stops to allow Nitrogen to purge from their bloodstream. A 20-25 minute bottom time dive at 235 feet requires somewhere in the 1.5 - 2 hrs of decompression stops I believe. __________________ Lake Winni - The only place I want to be during the summer. Last edited by Senter Cove Guy; 12-13-2005 at 06:04 PM.

12-13-2005, 02:03 PM	#4
Mink Islander Senior Member Join Date: Apr 2004 Posts: 753 Thanks: 59 Thanked 271 Times in 129 Posts	I think they cut over to Nitrox on the return once they get to a safe depth where the partial pressure of oxygen based on whatever EAN mix they're using is 1.6 bar or less, right?

12-13-2005, 06:31 PM	#7
Mee-n-Mac Senior Member Join Date: Sep 2003 Posts: 1,943 Thanks: 23 Thanked 111 Times in 51 Posts	Decompression Sickness I'm curious if the divers could settle an old question I have. Somewhere I recall reading or seeing some info that while decompression stops usually prevent the bends from occuring, it's not guaranteed. You can do everything "by the book" and still end up with bubbles where you don't want them ? Just curious .... __________________ Mee'n'Mac "Never attribute to malice that which can be explained by simple stupidity or ignorance. The latter are a lot more common than the former." - RAH

12-13-2005, 11:19 PM	#8
gtxrider Senior Member Join Date: Mar 2004 Location: Piscataway, NJ Posts: 1,030 Thanks: 2 Thanked 46 Times in 24 Posts	The bends Can the experts help on this question? Can you get the bends coming up to fast in shallow water? We were told that by our diving instructor. It also depends on the number of dives over a given time period. Did you ever notice that I you when hear a diver speaking on those very deep dives their voices sound funny? The helium in the mix does that.

12-13-2005, 11:55 PM	#9
warren Member Join Date: Apr 2004 Location: dunbarton Posts: 21 Thanks: 0 Thanked 0 Times in 0 Posts	shadow divers its a great story,the owner of the dive shop in concord nh. rob dove the u-boat this summer and said it was a wonderfull dive. he said the vis was not very good until he hit about 150 feet and then the the whole sub came into view underneath him. cool huh, warren

12-17-2005, 04:05 PM	#11
Senter Cove Guy Senior Member Join Date: Apr 2004 Posts: 604 Thanks: 298 Thanked 431 Times in 142 Posts	Additional Books To Read If you liked reading Shadow Divers, then you might also like the following 2 books: Deep Descent - A story about diving the Andrea Doria Last Dive - The complete story of the lives of the father & son team that died diving the U-869. __________________ Lake Winni - The only place I want to be during the summer.

12-18-2005, 11:43 PM	#12
Mee-n-Mac Senior Member Join Date: Sep 2003 Posts: 1,943 Thanks: 23 Thanked 111 Times in 51 Posts	Record dive Just to answer my own question as to how deep unprotected people could go ... I found that a few years ago somebody went to 1010 ft. Don't know the details but I guess the 600 ft I was wondering about (above) is indeed possible. Personally I think I'll leave the deeper than snorkel depths to an ROV. __________________ Mee'n'Mac "Never attribute to malice that which can be explained by simple stupidity or ignorance. The latter are a lot more common than the former." - RAH

12-19-2005, 11:53 AM	#13
Grant Senior Member Join Date: Jul 2002 Location: Pennsyltuckey, Tuftonboro, Moultonborough Posts: 1,504 Thanks: 382 Thanked 231 Times in 125 Posts	Oddly enough, we routinely hear about people taking DCS hits after what most would consider relatively shallow, short dives. In fact, I believe the author of "The Last Dive" took a pretty nasty hit after a rather basic dive. Took him out of commission for quite some time. So, yes, you can follow the tables, use a super-conservative dive computer, hydrate like a fish, take prolonged safety stops, use Nitrox, tri-mix, stay shallow, ascend slower than the slowest bubble, wear a rabbit's foot, pray, and still get hit. Today, in addition to the customary 3-5 minutes @ 15 ft. "safety stop," a lot of recreational divers are factoring in a short stop at a depth equal to 1/2 of their deepest point of the dive. Statistics suggest that this does indeed lessen the frequency of DCS. There are so many factors. Richie Kohler, one of the two primaries in "Shadow Divers" lives a few miles from where I'm sitting right now. The Jersey dive community is very active around here, and all the local shops have affiliations with the boats up and down the shore. The Rouses, the father-son team that died diving the "U-Who," dove out of my local shop, and the younger Rouse worked there. Some of their artifacts from the Andrea Doria are on display in the shop. __________________ "When I die, please don't let my wife sell my dive gear for what I told her I paid for it."

12-19-2005, 10:18 PM	#15
secondcurve Senior Member Join Date: Jan 2005 Posts: 2,120 Thanks: 1,333 Thanked 559 Times in 288 Posts	Grant & Senter Cove Guy: Thanks for the info on diving. Have either of you had problems or close calls when diving? I know that you proably haven't gone as deep as the divers in Shadow Divers but none the less, it seems risky even in waters as tame as Lake Winnipesaukee. How deep have each of you gone down? How many dives have you each made. Finally, isn't diving in Winnipesaukee kind of boring? Thanks for any input. Senter Cove Guy, I think I'm going to take your recoomendation and pick up a copy of the Last Dive. Thanks

12-19-2005, 11:11 PM	#16
Grant Senior Member Join Date: Jul 2002 Location: Pennsyltuckey, Tuftonboro, Moultonborough Posts: 1,504 Thanks: 382 Thanked 231 Times in 125 Posts	Funny you should ask... Actually, Senter Cove Guy and I live quite close to each other at the Lake, and dive together fairly often...when crappy weather and lack of air don't conspire against us... As far as depth, I've only gone as deep as 120', but not in Winnipesaukee. As I mentioned above, most of the good diving in Winni is much shallower than that. My max to date in the Lake is probably '70 or so. As for Winnipesaukee, it's FAR from boring. Lots of stuff to see. It's 70 square miles of puddle carved out by a glacier -- so the geologic formations alone are worth the price of admission. And the junk...don't get me started on the junk...and I'm but a newbie in this department. Page a forum member knows as Winnipesaukee Divers...he's a bona fide junkmeister general and a seriously seasoned diver. He's found all sorts of glorious refuse. I'm just in it for the fun and to see another side of the Lake I've loved all my life. If I find some treasures and see some critters along the way, bonus. If you're interested in hitting some of the cooler spots in the Lake, jump on one of the charters with Dive Winnipesaukee out of Wolfeboro. There aren't too many dive shops on the planet with a boat parked right out back! Wonderful folks who are more than glad to show you the popular sites around the Lake. Funny, at least two or three times a year, I have people approach me on the street in Wolfeboro, as I'm taking a cylinder to the shop, who ask me, "You actually dive in this lake? What on earth is there to see in there???" Kills me every time. Senter Cover Guy (left) and yours fatly, er, I mean truly, on the surface this fall about 7 hours south of Winni... __________________ "When I die, please don't let my wife sell my dive gear for what I told her I paid for it." Last edited by Grant; 12-21-2005 at 10:30 AM.

12-20-2005, 09:23 AM	#17
SIKSUKR Senior Member Join Date: Apr 2004 Posts: 5,075 Thanks: 215 Thanked 903 Times in 509 Posts	How come Grant and SCG are diving behind a Super Wal-mart in their water treatment pond?Just kidding guys!! __________________ SIKSUKR Last edited by SIKSUKR; 12-20-2005 at 02:27 PM.

12-20-2005, 10:13 AM	#18
Grant Senior Member Join Date: Jul 2002 Location: Pennsyltuckey, Tuftonboro, Moultonborough Posts: 1,504 Thanks: 382 Thanked 231 Times in 125 Posts	Because they needed underwater "greeters," and because WalMart pays so well. __________________ "When I die, please don't let my wife sell my dive gear for what I told her I paid for it."