Open Water Wreck Diving

[Vayu]

Greetings,

I am going to be diving a few wreck sites in deeper water (approximately 90') and on air in open ocean water for the first time. My question is simple, have you ever been blindsided by a wreck-specific dive problem? Are any particular currents associated with larger structures? These dives primarily concern the captain dan and rodeo 25 in the greater Ft. Lauderdale area, however any experience you would like to share would be appreciated regardless of site.

>V<

 

[DA Aquamaster]

Many open water wrecks are fished either commerically or recreationally. Commercial fishing can mean fish nets craped on the wreck - which are just nearly as effective at catching divers if you are not careful - and recreational fishing can mean monofilament line which can be hard to see and can entangle a diver if they are not careful and/or if they react badly when they first contact the line.

I have no clue what your level of experience and training is but at 90 ft on air there is the potential for your judgement to be less than perfect and that could lead you to succumb to the temptation to penetrate the wreck without proper training. Even large and open swim throughs can suddenly become hazardous if you or your buddy's actions or bubbles cause a silt out.

Have fun, be smart, stick to a pre-arranged plan for the dive that is well within your limits and always err on the side of safety.

 

[Diver0001]

Greetings,

I am going to be diving a few wreck sites in deeper water (approximately 90') and on air in open ocean water for the first time. My question is simple, have you ever been blindsided by a wreck-specific dive problem? Are any particular currents associated with larger structures? These dives primarily concern the captain dan and rodeo 25 in the greater Ft. Lauderdale area, however any experience you would like to share would be appreciated regardless of site.

>V<

Wrecks can be all snaggy like DA Aquamaster said. You *need* a knife or shears. Don't dive on a wreck without one. Also don't go inside. You can get lost 3ft from the exit and never know it. Dive with a buddy, especially on a snaggy wreck and plan the dive/dive the plan.

In terms of currents you'll find that one side may have heavy currents and the other will not. If it's big enough it creates a car-in-windtunnel effect and the currents will either shoot over you or you'll be able to find places behind objects to duck out of the currents if you need to. Some wrecks offer more protection from currents than others. I'm not familiar with the ones you're diving so you'll have to ask someone else about these particular ones.

Another interesting aspect of wreck diving is navigating around one. Your compass isn't reliable while swimming around large metal objects. If your viz is bad enough that you can't see the upline then you may need to work out some other way of not getting lost, like maybe clicking off to something near the upline and using a reel to lay out a guideline for yourself. You don't want to get lost and need to make a free-ascent because in doing so you may drift away from the boat. If you really can't find the upline, however, you'll eventually need to ascend anyway so you should also have signalling device like a DSMB, whistle, light or something along these lines.

Finally, procedures on the boat vary but there will be some new rules. Pay attention to the briefing.

R..

 

[Doc Intrepid]

Greetings,

I am going to be diving a few wreck sites in deeper water (approximately 90') and on air in open ocean water for the first time. My question is simple, have you ever been blindsided by a wreck-specific dive problem? Are any particular currents associated with larger structures? These dives primarily concern the captain dan and rodeo 25 in the greater Ft. Lauderdale area, however any experience you would like to share would be appreciated regardless of site.

>V<

Vayu,

Currents flowing over wrecks often behave somewhat like air moving over a wing. The current will be strongest on top of the wreck. If you're blown off the wreck by strong current, don't try to swim back to the wreck against the current - e.g. where the current is strongest. Drop down to the sand in the lee of the wreck, and pull and glide your way back to the wreck along the sand, then move back to the anchor line by transiting hand over hand across the wreck. Also, be advised that current close to wrecks can induce surge, where you can be sucked into openings, or thrown from side to side. Never penetrate inside the wreck structure without adequate training.

As DA said, monofiliament fishing line will be all over, and is nearly invisible. Carry shears, (not a knife) for wire leaders, and a second cutting device in case you drop the first. Plan your dive recognizing that your time for problem-solving is limited at that depth.

Dive as a team with a team mate and you'll be fine. Have fun,

Doc

 

[Vayu]

Thanks for the tips. Under no circumstances will I be penetrating these wrecks as I consider it technical diving on par with cave diving. I have some experience with narcosis and know there is little one can do about it on air except to dive the plan, relax, and have a few contingency plans for those unexpected emergency situations. 7 days countdown... let me know if you can think of anything else. Where do wreck divers clip their knives/shears?

-V

 

[captndale]

Thanks for the tips. Under no circumstances will I be penetrating these wrecks as I consider it technical diving on par with cave diving. I have some experience with narcosis and know there is little one can do about it on air except to dive the plan, relax, and have a few contingency plans for those unexpected emergency situations. 7 days countdown... let me know if you can think of anything else. Where do wreck divers clip their knives/shears?

-V

When diving on/in wrecks I carry two knives and one pair of shears or wire cutter. I carry a large knife with a serrated back and a hammer pummel for prying or sawing large line on the inside of my leg. I carry a medium sized knife and shears on my harness waist strap. I can reach any one of these tools with either hand. If I am installing or removing large lines such as mooring line (a frequent task) I also carry a pair of pliers or a shackle wrench in my pocket.

 

[MarkH]

In my opinion, one of the biggest hazards that most people seem not to care about is CO2 buildup. If you're swimming hard against a current you're probably breathing hard. Even with the best reg, you're still not getting the same amount of air as you would on the surface with no reg in you're mouth. Symptoms can be a headache and nausea or in severe cases, blackout. Even if you don't pass out, the "unwell" feeling may cause a diver to panic. Since I'm paranoid I think that this is a big factor in dive accidents where there is noticeable current.

 

[Vayu]

I try not to work or exert myself when playing around with these sorts of depths. In all likelyhood we will not be straying far from the line. Alot of you have mentioned currents. Assuming the bottom is not part of our dive plan, is it better to swim out or to grab the wreck?

-V

 

[Doc Intrepid]

If you're in a high flow, struggling to swim against it is never the wise choice. As Swankenstein mentioned, CO2 build-up can be swift and deadly. Get to a position where you can pull and glide against the current - move via your hands on the wreck, rather than struggling to kick against the current.

But your note about "the bottom not being in your plan" brings another caution to mind. (Granted you plan to dive air, however,) ensure that if you dive nitrox your MOD is about 10' deeper than the estimated depth to the sand. First, current can 'dig' deeper furrows around the stern or bow of a wreck than the average depth of the sand. Second, the wreck can settle in the sand so that, in it's lowest parts, you're actually a bit deeper than the sand. You don't want to have to go to the sand (e.g. after being blown off the wreck, for example,) and find yourself deeper than the MOD of your mix.

FWIW. YMMV.

 

[Diver0001]

But your note about "the bottom not being in your plan" brings another caution to mind. (Granted you plan to dive air, however,) ensure that if you dive nitrox your MOD is about 10' deeper than the estimated depth to the sand. First, current can 'dig' deeper furrows around the stern or bow of a wreck than the average depth of the sand. Second, the wreck can settle in the sand so that, in it's lowest parts, you're actually a bit deeper than the sand. You don't want to have to go to the sand (e.g. after being blown off the wreck, for example,) and find yourself deeper than the MOD of your mix.

FWIW. YMMV.

This is excellent advice.

R..