Bag for shooting Ironmans?

My wife does Ironmans, and so of course I play photographer while she races. For those who don't know, Ironmans (even for fast amateurs like her) take about eleven hours, so it's truly an all-day sort of thing. In the past I've used a general backpack with some towels for padding, but that's not ideal and not what I want to be doing at Kona. The plan is to take the 5D3, a 24-70/2.8ii and 70-200/2.8ISii, I'm torn between a sling bag (maybe the TurnStyle 20), but some people are saying they're not comfortable for extended periods. That would lead me to a dedicated camera backpack, though that's probably bigger than I really need just for that. I was looking at the Karachi Outpost (S). What are some other good options?

Some questions to narrow down the options:
* do you need to carry anything else, other than camera gear?
* do you need fast access? i.e. without taking the bag off?

One option is a chest mounted toploader bag, like the Lowepro (http://store.lowepro.c​om …ng/toploader-pro-75-aw-ii). That one takes a mounted 70-200 2.8, and you can attach a lens case on the side for the 24-70 - I have this setup.

Lowepro have a chest mounting harness. They specifically market this kind of combo for runners/hikers who want very quick access to their gear.

I have the chest harness, but don't use it because the times that I want the bag chest mounted, I also have a large backpack on - so I attach the bag to the shoulder straps of the large pack.

I do use the toploader (with lens case), slung over one shoulder, for hiking, and it's fine. It has a stabiliser strap, but it's a bit too loose for running.

definitely stick with a backpack. Having weight off center all day is hard on the body.

Check out this to mod your current pack:

http://trekpak.com

dodgyexposure wrote in post #18355651
Some questions to narrow down the options:
* do you need to carry anything else, other than camera gear?
* do you need fast access? i.e. without taking the bag off?

One option is a chest mounted toploader bag, like the Lowepro (http://store.lowepro.c​om …ng/toploader-pro-75-aw-ii). That one takes a mounted 70-200 2.8, and you can attach a lens case on the side for the 24-70 - I have this setup.

Lowepro have a chest mounting harness. They specifically market this kind of combo for runners/hikers who want very quick access to their gear.

I have the chest harness, but don't use it because the times that I want the bag chest mounted, I also have a large backpack on - so I attach the bag to the shoulder straps of the large pack.

I do use the toploader (with lens case), slung over one shoulder, for hiking, and it's fine. It has a stabiliser strap, but it's a bit too loose for running.

* Can't hurt to carry some extra stuff - snacks and water especially.
* Not really fast access; there are timing checkpoints that let you fairly accurately predict when someone will arrive, and that's on top of the whole affair being planned within an inch of its life prior to leaving. In the past I've pulled it out maybe 10-20 minutes ahead of each time she'll appear. The run it may stay out longer, but that's only a few hours. Unlike wildlife, she's not going to unexpected appear atop a tree and disappear a few seconds later.

I'm not sure I'd want a chest harness, from the looks of it - I think the backpack would actually be less obtrusive throughout the day while walking around. And, as noted, it has the advantage of being able to carry around some extras at the same time.

Are there any other backpacks out there that would be suitable? I'd like one, ideally, that isn't black nylon screaming "I'm a camera bag!" for the world to see, which is what appealed to me about the Crumpler, but I'm certainly open to alternatives.