It appears you have not yet registered with our community. To register for free click here
Rebreather World
       

Go Back   Rebreather World Rebreather Training Decompression & Gas Choices

Reply
 
LinkBack Thread Tools Display Modes
Old 23rd October 2012, 20:10   #1 (permalink)
RBW Member
 
Dsix36's Avatar

 
rEvo
Optima Dolphin
Join Date: Aug 2007
Location: Deerfield_Beach, Florida
Posts: 3,487
Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute
Loooooong dives with air breaks ???

OK, I am planning a rather big dive and am looking to be in the water for 6 hours or more. About 4 hours of this will be deco. I am wondering what others have been doing to manage high CNS with similar dives?

Please only respond if you have actually done a 6 hour dive with significant deco.
(Offline)
 
Digg this Post!Add Post to del.icio.us
Reply With Quote
Old 23rd October 2012, 20:26   #2 (permalink)
CCR Newb
 
CaveDive1's Avatar

 
rEvo
Join Date: Aug 2011
Location: Central Florida
Posts: 84
CaveDive1 has a little shameless behaviour in the past
Re: Loooooong dives with air breaks ???

Quote: (Originally Posted by Dsix36) View Original Post
OK, I am planning a rather big dive and am looking to be in the water for 6 hours or more. About 4 hours of this will be deco. I am wondering what others have been doing to manage high CNS with similar dives?

Please only respond if you have actually done a 6 hour dive with significant deco.

Does a chamber count? 5 minute air break for every 20 minutes of pure O2
(Offline)
 
Digg this Post!Add Post to del.icio.us
Reply With Quote
Old 23rd October 2012, 20:30   #3 (permalink)
RBW Member
 
Dsix36's Avatar

 
rEvo
Optima Dolphin
Join Date: Aug 2007
Location: Deerfield_Beach, Florida
Posts: 3,487
Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute Dsix36 has a reputation beyond repute
Re: Loooooong dives with air breaks ???

Quote: (Originally Posted by CaveDive1) View Original Post
Does a chamber count? 5 minute air break for every 20 minutes of pure O2
Details of a chamber ride won't work for me. Having an O2 seizure in the chamber won't cause you to drown.
(Offline)
 
Digg this Post!Add Post to del.icio.us
Reply With Quote
Old 23rd October 2012, 20:35   #4 (permalink)
CCR Newb
 
CaveDive1's Avatar

 
rEvo
Join Date: Aug 2011
Location: Central Florida
Posts: 84
CaveDive1 has a little shameless behaviour in the past
Re: Loooooong dives with air breaks ???

Quote: (Originally Posted by Dsix36) View Original Post
Details of a chamber ride won't work for me. Having an O2 seizure in the chamber won't cause you to drown.
You're probably right, but the O2 procedures are the same. 30 minutes on, 5 minutes off. Unless wearing a helmet is also an issue.

I/We changed it to 20/5 because I was paranoid. Doubt it really mattered.
(Offline)
 
Digg this Post!Add Post to del.icio.us
Reply With Quote
Old 23rd October 2012, 22:39   #5 (permalink)
RBW Member
 
Hagberg's Avatar

 
homebuilt SM, mod. Azimuth CCR
Join Date: Aug 2008
Location: Florida
Posts: 11
Hagberg is an unknown quantity at this point
Re: Loooooong dives with air breaks ???

Quote: (Originally Posted by Dsix36) View Original Post
OK, I am planning a rather big dive and am looking to be in the water for 6 hours or more. About 4 hours of this will be deco. I am wondering what others have been doing to manage high CNS with similar dives?

Please only respond if you have actually done a 6 hour dive with significant deco.
Keep PO2 low during the working/bottom phase of the dive, and then take low-PO2 breaks while on Oxygen during deco. Doing 12 minutes on Oxygen and breaking for 6 minutes seems to enable you to stay alive for a very long time. For the limited deco you are looking at you might get away with doing 15 on, 5 off as well. (Easier numbers than 12 and 6) Keeping Helium content high may be beneficial in limiting CO2-buildup and perhaps also risk of tox.
Antioxidants before and during a dive has likely not hurt anyone either. I like Propel in a Camelback pouch for long dives. :)
(Offline)
 
Digg this Post!Add Post to del.icio.us
Reply With Quote
Old 23rd October 2012, 23:12   #6 (permalink)
WEB MERMEN
 
wizbang's Avatar

 
Inspo-Meg-PosMkVI-CCRDolphin
Prism,rEVO,Mk15.5,KISS,Hmblds
Join Date: Feb 2005
Location: Perth Australia
Posts: 429
wizbang has a spectacular aura about wizbang has a spectacular aura about wizbang has a spectacular aura about wizbang has a spectacular aura about wizbang has a spectacular aura about wizbang has a spectacular aura about
Re: Loooooong dives with air breaks ???

Dsix36 you don't mention what your current longest dive is (deco wise) and the CNS percentages you are experienced with and happy to tolerate.

If you are a strict 80% man then there will be a lot more "air" breaks if you have a tendency to hit the 100 odd mark then there will be less need for breaks.

With the deco being 4hrs of 6hrs I am imagining it not to be too deep.
If this is the case I would suggest managing the CNS and therefore the need for air breaks with a lower setpoint for bottom time.

Hope the info helps.
Wiz
(Offline)
 
Digg this Post!Add Post to del.icio.us
Reply With Quote
Old 23rd October 2012, 23:21   #7 (permalink)
breathing or rEbreathing
 
Davydive's Avatar

 
rEvo Mini/Micro FT, CKiss #039
Halcyon PVR-BASC, Dolphin, Ray
Join Date: May 2007
Location: Singapore
Posts: 683
Davydive has a spectacular aura about Davydive has a spectacular aura about Davydive has a spectacular aura about Davydive has a spectacular aura about Davydive has a spectacular aura about Davydive has a spectacular aura about
Re: Loooooong dives with air breaks ???

What about some fitness routine and preparation?
I am sure Kim and Peter can attest to that on their big Cayman dive.

Cheers!
__________________
* There is no such thing as ZERO risks!
* Don't Learn Safety By Accident.

(Offline)
 
Digg this Post!Add Post to del.icio.us
Reply With Quote
Old 23rd October 2012, 23:23   #8 (permalink)
RBW Member
 
donlabbruzzo's Avatar

 
Join Date: Dec 2007
Location: El Paso, TX
Posts: 207
donlabbruzzo will become famous soon enough donlabbruzzo will become famous soon enough donlabbruzzo will become famous soon enough
Re: Loooooong dives with air breaks ???

Please be more specific with the details of the dive, MOD, Dil. Bottom time, deco time and run time.

As was already mentioned, long dives such as this require lower PPOS set points, typically 1.0 throughout the dive and possbily 1.2 to 1.3 for some portion of the 40' - 20' stops.

Depending on the MOD, it's unlikely you'll have Air to use during the "Air" breaks. if you're carrying 50% as a bailout gas, that's what you'll have to use for the breaks off 100%.

It's almost impossible to have a reasonable deco time without exceeding the OTU's during a six hour dive. Your CNS willl be manageable if your set points are kept low during the bottom portion of the dive.

I've made several 5 hour dives and exited the water far pasted the allowable OTU's. Not too much you can do.

Don
(Offline)
 
Digg this Post!Add Post to del.icio.us
Reply With Quote
Old 24th October 2012, 00:17   #9 (permalink)
RebreatherWorld Sponsor

 
Lancer4545's Avatar

 
Meg/Shearwater Pathfinder
Join Date: Jun 2007
Location: Cairns QLD Australia
Posts: 1,929
Lancer4545 is a splendid one to behold Lancer4545 is a splendid one to behold Lancer4545 is a splendid one to behold Lancer4545 is a splendid one to behold Lancer4545 is a splendid one to behold Lancer4545 is a splendid one to behold Lancer4545 is a splendid one to behold Lancer4545 is a splendid one to behold Lancer4545 is a splendid one to behold Lancer4545 is a splendid one to behold Lancer4545 is a splendid one to behold
Send a message via Yahoo to Lancer4545 Send a message via Skype™ to Lancer4545
Re: Loooooong dives with air breaks ???

Quote: (Originally Posted by Dsix36) View Original Post
Details of a chamber ride won't work for me. Having an O2 seizure in the chamber won't cause you to drown.
Wear a FFM and you'll stand a much better chance of surviving a CNS event also...........
__________________
You can run but you can't hide!

ISC Appointed Megalodon Dealer for East Australia
ISC Trained Megalodon & Pathfinder Trimix Instructor & Service Technician
http://www.closedcircuitdivers.com.au
info@closedcircuitdivers.com.au
(Offline)
 
Digg this Post!Add Post to del.icio.us
Reply With Quote
Old 24th October 2012, 00:26   #10 (permalink)
RBW Member
 
jkaterenchuk's Avatar

 
HammerMeg
Kiss Classic, Inspiration
Join Date: May 2006
Location: PA
Posts: 2,928
jkaterenchuk has a reputation beyond repute jkaterenchuk has a reputation beyond repute jkaterenchuk has a reputation beyond repute jkaterenchuk has a reputation beyond repute jkaterenchuk has a reputation beyond repute jkaterenchuk has a reputation beyond repute jkaterenchuk has a reputation beyond repute jkaterenchuk has a reputation beyond repute jkaterenchuk has a reputation beyond repute jkaterenchuk has a reputation beyond repute jkaterenchuk has a reputation beyond repute
Re: Loooooong dives with air breaks ???

Don't forget to take into account hyperthermia and the effect a lower body core temperature might have upon the efficiency of your off gassing as well as its a bitch to be shivering for the last 90 minutes of deco.

John
(Online)
 
Digg this Post!Add Post to del.icio.us
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT. The time now is 12:34.


RebreatherWorld.Com 2005 - 2013
Rebreather World, RBW and the Rebreather World Logo are Trademarks
All rights reserved, no republishing of content without written permission.
By using this website you have agreed to our Terms & Conditions of Use

free counters

Search Engine Optimization by vBSEO 3.1.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780