• Welcome to ScubaBoard

  1. Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

    Benefits of registering include

    • Ability to post and comment on topics and discussions.
    • A Free photo gallery to share your dive photos with the world.
    • You can make this box go away

    Joining is quick and easy. Login or Register now by clicking on the button

Ditching run time

Discussion in 'Hogarthian Diving' started by lefrogster, Feb 27, 2014.

  1. RJP

    RJP Scuba Media & Publications

    # of Dives: 1,000 - 2,499
    Location: New Jersey
    Unless that "3min late" is late leaving the bottom... and your computer now tells you that you'll be 18min late getting back on the boat.

    Working on a boat, I can't tell you how often I hear someone come up late saying something like "I don't know what happened. My computer was giving me 10min of deco when I went after that lobster. It only took me like five minutes to bag him, but when I looked at my computer again it was giving me 32 minutes! What a piece of crap..."
    kwinter and nimoh like this.
  2. PfcAJ

    PfcAJ Orca

    # of Dives: 5,000 - ∞
    Location: St Petersburg, Fl
    Its also additive on the deeper portion of the ascent, and it gets more pronounced the deeper you are.

    Take a 200' dive. Extra time spend at 120' when you really should be at 70' could mean the deco plan you're using isn't as appropriate as it could've been if you didn't dillydally through the ascent.

    RT is a useful tool.
    Last edited: Mar 10, 2014
  3. Wookie

    Wookie Secret Field Agent ScubaBoard Business Sponsor

    If I can see you on a line decoing somewhere, or I'm following your bag, I don't really care when you get to the surface (within reason). An exact to the minute schedule is something nice, but not the object of the sport.
  4. rjack321

    rjack321 Captain

    # of Dives: 1,000 - 2,499
    Location: Port Orchard, WA
    By the same token I have seen tech instructors sit and wait at 150ft on the way up from an aborted 210ft dive. Bottom time was <5mins (wreck wasn't there) and they had no idea how to adjust their deco schedule to match the actual deco obligation. So they sat at 150ft (their first deep stop) for 15mins to get back onto their pre-planned schedule.

    "Breaking runtime" doesn't always mean the deco time gets beyond what you brought gas to accomplish.

    I don't actually use (total runtime), never have. We do have a good understanding of our maximum allowable deco based on the gas we have, and strategies for completing the deco within a given time frame (typically plus/minus 10mins, sometimes more sometimes its much tighter like plus/minus a minute)
  5. DevonDiver

    DevonDiver N/A

    # of Dives: 5,000 - ∞
    Location: Subic Bay, Philippines
    Another perspective... the stress of following basic tech procedures on a strict schedule is a diver-originated issue. i.e. task loading versus ingrained skill

    1) Most dive planning software allows you define extra time, within the run-time, for completion of gas switches. Or you can manually add that (slates). This works if doing 'team switches' using formal procedure (NOTOX) once reaching the deco level.

    2) Many technical divers prepare for the gas switch during the 'free-time' on ascent to the stop/gas-change. This basically re-orders the NOTOX protocol; on ascent to stop - confirm the tank/markings, deploy the regulator, turn the cylinder on, confirm team mate has prepared the right gas (trace regulator to cylinder and confirm markings).... on arrival at the stop; confirm above MOD, signal, gas-switch, examine buddy again (trace regulator to cylinder and confirm markings). That is seamless and very quick.

    I teach both methods on my courses. What matters is that all critical steps are completed before you breath the regulator... and that a physical/visual confirmation of buddy/team is completed during or immediately after the switch.

    There is no reason PADI courses can't be run with sequential (or team) switches. But why blow run time, when you can just anticipate your needs in dive planning?

    Run-time is pretty useful... and much easier to follow than stop-times alone.

    I don't really understand why your instructors would have you plan/mark a run-time, then condone breaking it as a routine. It sounds lazy to me...

    Which makes a good argument for planning/preparing ahead... and making use of your ascent to stop, when you have nothing else to do... :wink:

    Task-loading and stress is a diver/skills issue, not a procedural issue. It seems like you are asking for validation to abandon a proven, tested procedure, to compensate for personal difficulties you are experiencing.

    You WILL find the task-loading and stress decreases as you gain more experience and competency. Re-visit this thread after another 100 technical dives and you'll see what I mean :wink:
  6. RJP

    RJP Scuba Media & Publications

    # of Dives: 1,000 - 2,499
    Location: New Jersey
    Not understanding the change to your schedule when the dive runs short is just as bad/lazy as not understanding it on the long side... albeit with less likelihood of a helicopter ride afterwards.
    waterpirate likes this.
  7. wedivebc

    wedivebc CCR Instructor ScubaBoard Supporter

    I am not getting this at all.

    When I was trained and when I teach (remember the original question was about a class) we calculate a plan and a contingency, we allow time for task loading skills such as throwing a bag and gas switches and we all ascend together as a team.

    What I am seeing here is more like SOSD dives with very loosely held schedules.

    If we just jump in the water and swim around willy-nilly then ascend on our computers, aren't we just rec divers with extra stuff?

    I think we should treat tech training as a formal event and practice precise team and time management. What you do after training is your business.
  8. RJP

    RJP Scuba Media & Publications

    # of Dives: 1,000 - 2,499
    Location: New Jersey
    Dive until your computer starts beeping... exit water... stay out until your computer stops beeping. Repeat.
  9. Redshift

    Redshift DIR Practitioner

    # of Dives: 200 - 499
    Location: Finland
    I don't think people are saying it's ok to delay ascent or to hang around doing something when they should be going up. I think the point is that it may be difficult for a team to have exactly the same runtime, to perform all the tasks within it and to accommodate for anything that could happen and that it's not as enjoyable for some people and may not make much difference in the end.

    Will every member of the team have the computer / depth gauge turning on at the same time? No. I have seen it countless times. Therefore someone on the team will have to redo the whole runtime. Will everybody swim at exactly the same pace and be at the same position? No, especially when going up a shotline. What if starting the ascent one was a bit slower, will it exceed max ascent rate to meet runtime? I wouldn't. What if sending up the smb takes a little longer? I don't think (or at least don't hope) anyone is advocating not caring about times at all, but that runtime to the minute may not be necessary when it's easy to be one minute off switching gases or one minute off sending an smb. What will the difference be in deco? And among the huge variety in deco models and different parameters are those couple of minutes any important? If a stop is at Xm are you never at X.3m?
  10. Nasser

    Nasser ScubaBoard Supporter ScubaBoard Supporter

    In the beginning when I was first learning to follow Run Times, stay within the various descent and ascent rates, and hit the gas switches on the mark I felt pretty task loaded and a little overwhelmed. But like anything, after more practice I become much more fluid and relaxed. Now I find following Run Times and doing gas switches quite easy to execute and don't even feel the need to pad my times for switches during ascents. If I so choose, the options are there with the deco software we use, but I have not found the need for that. Plenty of practice, good team communication and awareness, and feeling relaxed during the dive is the key.
    Micksherryn likes this.

Share This Page