Help Me Think Through Maximizing My Time

[Cacia]

I am trying to plan the longest safe profile possible to shoot freedivers on the plane at 107 ft. I have been lucky enough to scrape up a Navy Dive School "buddy, support diver" so I have somebody to back me up if I get loopy...

The issues are longer bottom time because the freedivers need surface time to deep breathe, rest, etc

They might have time to only make a couple passes to 107.

here is what he wrote me (planning..)

Once she's down, Derek and I will only get to descend a handful of times since her bottom time is only ~10 min. In fact, considering that freediving to this depth requires almost 2:00, and the minimum recovery time after diving this deep is 4:00 (preferably 8:00), this theoretically only affords Derek and I time to make two dives each for the deep photographs. This is why I think it would be worthwhile to plan the photo ops as well as possible beforehand. A way to add more photo ops is bring along another freediver (Morgan, freedives to 130ft, underwater photographer for BBC), so that there more of us alternating on going down.

I have more than 10 minutes, but I am used to working with that number due to my state of mind on air over 100 ft.

Any ideas? I was wondering if there is a profile I could implement where I ascend halfway while they rest...I need to be exact so it all gets orchestrated optimally.

So, the goal is to have everyone in a place for an image to transpire, while maximizing the bottom time. Any help or creativity appreciated!

Obviously, scraping up some EAN would be nice. .32 probably as rich I should use.. what's the MOD for .34 ?

Someone will be on the boat for shallow water blackout reasons.

Any issues I am missing?

 

[Benthic]

As you've mentioned EAN would increase your available bottom time, and would likely help a bit with any narcosis issues. I'm not aware of any 'creative' profiles that will allow you to earn back bottom time by coming shallower while the freedivers are resting. That sounds like a 'sawtooth' to me, which probably isn't a good idea.

I must admit I don't know your background so forgive me if I speak out of turn here, but have you considered going into deco? If so you could spend 30 to 40 minutes at 100 feet (on EAN32) with a very minimal deco obligation. By minimal I mean barely more than a safety stop. And that's assuming you'll deco on the EAN as opposed to oxygen.

Of course, appropriate gas reserves, etc are always a consideration too. There are certainly ways to stay at 100 feet for a long time. It's just a matter of how badly you want to be there.

Brian

 

[Cacia]

I considered that, but we don't dive doubles and I don't want to count on his air since I have never dived with this guy before....

Yes, the sawtooth was not sounding ideal to me either, I just wondered if I was missing something obvious.

Ideally, I won't get into deco and will do a half deep stop, and a long safety stop. (on a line...sometimes there is a lot of current, it's three miles offshore)

I like to keep in mind that I don't have 02 on my boat.

Another thought would be to take a long SI and do a second dive.

 

[Benthic]

Well if you don't want to incur required deco then I think you're on the right track with the EAN32. That should give you a solid 25 minutes on the bottom, which is enough time for each of your free divers to make two passes in front of your lense. Then, if need be, you can make a second dive after a surface interval of an hour or so, and each free diver can get two more passes in front of the camera.

Not to mention the fact that if your buddy is a 'new to you' you may not want to walk too close to the edge anyway.

Brian

 

[ianr33]

What tank are you planning on using? Unless you have an amazing SAC rate an Al 80 will not give you a decent reserve after 30 minutes at 100 feet

If doubles are not an option why not sling a second 80 with 32% in it? That will give you loads of gas and redundancy. (Of course you will also be a stroke for using independant doubles but that is another story )

On the way up stop at 50 or so for a couple of minutes then do a bunch of safety stops at 30,20 and 10

 

[Benthic]

Okay, Okay, so just for fun I plugged this into V-planner to see what would happen.

Descend
100' for 5:00
60' for 10:00
100' for 5:00
60' for 10:00
100' for 5:00
Surface

This profile would give you three passes at each free diver instead of two and according to V-planner it would be a no-stop dive. Sawtooth profiles are notoriously hard on the body though so best to have plenty of gas for that safety stop.

I still think the best way to do this is to go to 100' and stay there--but if required deco isn't an option then this is something to consider. Of course the 'choreography' of the whole thing could get interesting.

As a 'last ditch' option, you could always buy me a ticket to Hawai'i. I'd be happy to pack up the Meg and shoot the photos for you.

Brian

 

[Cacia]

e

I'd like to bring my chum too. I think we could draw in some sharks if
nothing else.

...NO CHUM...here: I need to practice saying this: "hell, no, boys" or "after I get out...knock your socks off!@#%##$"

oh great...what I go through. I am still having nightmares from the last time freedivers got the sharks all worked up. The bad part is they all have these 12 foot spearguns and I have NOTHING. WAAA. I want TWO buddies, a pack..."a team!"

Descend
100' for 5:00
60' for 10:00
100' for 5:00
60' for 10:00
100' for 5:00
Surface

yes, thats what I was thinking of, but I am so not in the habit of doing that...i think it would make me paranoid. (no o2, etc) So...I might just get the EAN and limit myself to the 20 minutes. What is a MEG?

Of course the 'choreography' of the whole thing could get interesting.

you are thinking just like I am. I have done them before and the tendancy you fight is following them up and down too much.

So, EAN .32 and descend after they are "ready"

Unless you have an amazing SAC rate an Al 80 will not give you a decent reserve after 30 minutes at 100 feet

It's good enough for 20-25. I'll keep a close eye on it. I really cannot be slinging bottles with a big camera and a strobe arm...I just know I could not..too much drag because the current there requires you to swim. (I try hard not to exert myself on deep dives) Good thought though, I bet NAVY-boy could sling a bottle if that's all he has to keep up with. Yes, I like that.

No, they do not need the chum, their wetsuits smell like fish guts already, I have deduced. Tigers follow them around like lonely puppies. They see them on so many dives...a 14 ft one just the other day on the YO...I have NEVER seen one there. Okay, I am scaring myself with this field trip.

Of course you will also be a stroke for using independant doubles but that is another story )

that's okay...on the bike forum, I get to be "a Fred".

 

[JeffG]

What is a MEG?

Megladon Rebreather.

 

[sea nmf]

Why couldn't you hand a tank & reg to do deco?

 

[Cacia]

handle?

I just don't do deco...on purpose that is. If I buy a few minutes, I can accept that, but I don't ever plan it. Usually, I get into it by descending a little too slow due to taking pictures. That's my buddies job, keeping an eye on that. I could learn it, but not when doing something new for the first time. By the time I deal with the boat, the GPS, I have no more RAM.

I have my way and I need a big fudge factor because I get easily distracted.

I keep my task loading the KISS method. But...having the buddy sling a tank is good idea. If he went through the Navy dive school, I think I can assume he will be able to do that.

I do like the planning, but honestly, my main goal is to limit what I have to think about down there. I don't know how divers dive without computers and take pictures at new sites and all...they have explained it to me, but I know my limits.

great, I'd be down there doing a deco with all their pets.. and they would be hightailing it to the boat....that is really starting to annoy me.