Trees at Windy Point - Experience Level?

[ianr33]

Probably my favorite place to dive in Travis is in the trees at Windy Point. With a full lake these start at around 100 feet . Some of them are a good size,maybe 1 foot diameter trunk and 30 feet tall. Later in the year when the "windex" layer forms it is surreal to break through the muck above and drop down into the cold,clear world below.

Lets consider a dive to 120 feet for 15 minutes. Do this on 28% nitrox and it is within recreational parameters (albeit it on the deep side)

What level of experience/gear configuration is appropriate for this dive?

 

[loosebits]

Personally, I do not feel comfortable being that deep in a Texas lake without doubles or the redundant gas source of your choice (I have no delusions of being able to make a CESA from 120'), just make sure its enough to bring you up from 120 at much slower than 30 fpm (because you don't want to ascend straight up into boat traffic but along the bottom).

You'll want some sort of navigation aid, either a compass or a reel (if trained in reel use). You can get into areas where it flattens out and difficult to discern the slope of the bottom and thus the way up.

I would also want a lift bag to aid a direct ascent if one was absolutely needed (a bottom-following ascent would take far longer than a direct ascent).

I would want a nice bring primary light and at least one backup. If your buddy's light is significantly brighter than yours, you're in front because you won't be able to signal him from behind.

At least 2 knives, preferably one of them a z-knife (monofilament), neither of them should be worn on the leg, this is one of the worst places you could put a knife and its just asking to get caught on something.

An aware buddy.

As far as experience, good buoyancy control is a must and anti-silting techniques is a definite plus (a flutter is going to tear it up down there). I would also work up to that depth. Diving 120' in Cozumel and 120' in Travis are two different things. It's cold and it's dark down there, you should make sure you're are comfortable with the narcosis before such a dive. I did quite a few dives in the 90 - 115' range in Travis before I started going deeper. You'll also want a better understanding of gas management then "be back up with 500 psi". What is your SAC? What is your buddy's SAC? How much gas will it take to get both of you to the surface in a stressful situation?

These are just the things I can think of, YMMV

 

[ReefHound]

I would agree it's something to build up to, get in a dozen dives there at 80' to 100', a pony bottle would be nice. I would add being Rescue level, it teaches you to slow down and react calmly, of course there is no substitute for practice. If possible, go with someone who's already been to that level there a number of times.

 

[Crazyduck]

Loosebits- excellent write up!
I agree with everything said.

Dives below 100ft are borderline technical dives.
28% nitrox at 120ft is a PPo2 of 1.3
28% nitrox at 132ft is a PPo2 of 1.4 (that’s pushing the PPo2 for me)

For me 1.2 is preferable for PPo2.
24% nitrox at 132ft, O2 exposure at 1.2 for 30 minutes is 15% of your total o2.
I am adding the extra depth in case you were to drop 10ft and did not notice it.

NAUI air table’s state 120 ft for 10minutes is limit before pushing the table, for example 25 minutes would give you in the neighbor hood of 6 minutes deco in a square profile.

So you have to add into your profile any deep stops (Pyle stops or m-valve curve) then add in other components such as shallow stops and how long. Including safety stops.

I am not sure what you are using for a dive computer but you might want to consider at least a single gas nitrox or preferably a dual gas nitrox. While computers are far from the ‘be all’ for deeper diving it helps to look at profiles, ascent rate, start and stop times. Your computer needs to calculate you deco information in minutes not bars and circles. But that is a topic within itself.

It would be good to find a mentor or a group of guys who will start working with you. Your transition needs to take time and your mentors need to ask you questions and make you stretch and grow.

In closing start reading on decompression and consider classes to assist you.
Happy hunting, Andrew

 

[ianr33]

Just to make clear. I dive the trees regularly when the conditions are good,and I know how I choose to do it. Want to see how others aproach it.

So far we all seem to be pretty much on the same page. i.e. treat it as a technical dive due to depth,silt out possibilities,entanglement hazards and the difficulty of making a direct ascent to the surface (tree branches above you,crappy viz with no visual references and possible boat traffic)

 

[FIXXERVI6]

100+ in a lake, I treat it as a technical dive, everything loosebits mentioned, I use 32% down to 110 feet beyond that I use air, I used to dive the 28% and 26% but the benefit is just goofy vs. paying the difference between air and nitrox for such little benefit, if I had my own brew station in the garage sure I'd keep diving leaner mixes.

My personal ppo2's 1.4 max ppo2 on bottom mix, 1.5 max ppo2 and deep gas swtiches/stops 1.6 max ppo2 on shallow deco (oxygen)

I don't hit tripple digits witout doubles in a lake the whole "my buddy is carrying my extra air" doesn't work so well when he is 5 feet away and you can't see him in spots, not that my buddies ever get away but you know how it goes, if you ARE going to have a gas failure it will happen at the worst moment.

One thing I wonder if people consider is the deco aspect, if they dive deep within NDL, do they consider that they could be racking up deco if say they got hung in fishing line and had to take an extra 10 minutes to get free, will they have the gas to finish it up and do the stops? I have heard of cases of DCS where that has happened and people were not able to complete their stops.

 

[outback]

One thing I wonder if people consider is the deco aspect, if they dive deep within NDL, do they consider that they could be racking up deco if say they got hung in fishing line and had to take an extra 10 minutes to get free, will they have the gas to finish it up and do the stops? I have heard of cases of DCS where that has happened and people were not able to complete their stops.

Definitely a possibility in the trees at Travis. We did some IANTD tech training there to 140+ (air + 50% deco mix) - it's dark, cold, easy to silt up and if you get out the other side of the trees where they're thinnest (round about where the chain line goes down to 100' if I remember corectly) the currents in the lake tend to ball and gather fishing line. Though that's around 160' so hopefully not an issue.

If you're going through the trees, I'd recommend running a line and treating it as an overhead environment - if you have to make a direct ascent through the trees it would be real easy to get caught up in the branches and blow your NDL - especially as you may have to go back down before finding a route up and out.

Also worth watching for is your orientation in the water - it's very easy to fin down slope, dark but clear ahead, but unless you're watching your backwash, you can turn around and find yourself faced with a wall of silt (ie a horizontal attitude will send backwash into the slope behind you - as we discovered - you want to orient your body parallel to the slope).

 

[Crazyduck]

Want to see how others aproach it.

Approach it how?
Gear, gas management, team structure, reels, scooters?
I am interested in the conversation but not quite sure where you want to take this?

Andrew

 

[ianr33]

Approach it how?
Gear, gas management, team structure, reels, scooters?
I am interested in the conversation but not quite sure where you want to take this?

Andrew

What I wanted to know was if anybody actually treats it as a recreational dive. It always feels like a technical dive to me ,even though in the original example it is within recreational limits.

 

[loosebits]

Well, I'm sure there are plenty of people out there diving it with a single yoke AL 80.

It's all about how much risk one is willing to assume but this thread is good in that some of these people may not be fully aware of the added dangers of diving in this area.