Difference between wreck and cave diving?

[DA Aquamaster]

With redundant doubles you would turn the post off on the freeflowing reg to stop the flow. A failed burst disc or an extruded neck o-ring is different in that you could isoloate the tank with the failure but would still lose a lot of the gas and that could silt out the cave/wreck. In most cave training one of the first things you do in an emergency air share drill is get on the line, because in that situation there is elevated risk of a silt out so you want to be one the line and pointed out to save time if the viz goes while the air loss and if nneded air sharing is established.

Percolation is what it is called when just your normal exhaust bubbles bring down silt or mung from the celiling. It can be pretty normal in many cave or wreck environments and can vary from a diving in a snow globe effect to a more complete loss of viz depending on the type and amount of silt.

I had a situation during my most recent dive in Ginnie where percolation brought down a football sized rock that impacted the bottom of my tanks. But that is a very unusual event and is more a case of being in the wrong place at the wrong time.

 

[NorthernShrinkage]

The only things taken from wrecks should be the good stuff dropped by previous divers Past that leave things alone to be enjoyed but others who have the skills to get where you have been......

 

[MXGratefulDiver]

The only things taken from wrecks should be the good stuff dropped by previous divers Past that leave things alone to be enjoyed but others who have the skills to get where you have been......

That seems to be a difference between east coast and west coast wreck divers. Back east, taking stuff seems to be the point of diving the wrecks. On this side, taking anything off the wreck is seriously frowned on, and can get you disinvited from the next dive ...

... Bob (Grateful Diver)

 

[Gilldiver]

You forgot the hammer and crowbar ...

... Bob (Grateful Diver)

When doing serious wrecking I personally will only take a pry bar in my wreck/tool bag. A crowbar is only taken when a specific job/action is planned that would use it.

Also in the wreck bag inner section are:
Vice grips
Flat blade screwdriver
Punch Pin (used to drive porthole hinge pins etc.)
Sometime a campers Multi-tool

In the outer section
Jon line
50 or 75# lift bag
US Navy air table (just because)
A Small reel is also clipped onto it

On my weight belt is a 4# hand mallet

The pizza stained T-shirt stays on the boat.

But for non-tourist wreck diving - in other words natural wrecks, not clean up ones:

One of the biggest difference is that in wreck diving, at least in the North East, is that your major travel distance are vertical. Wreckers try to hook a wreck as close to the area of interest, or opening, as possible to minimize horizontal travel. This means that the majority of a long deco dive will be in open water. The result is that many times the dive is much more square then a cave dive may be.

Cave diving almost by definition will have much longer horizontal distances to travel with much less vertical. This means that your deco may/most likely will be done to some part in the overhead area etc.

Other differences are that if the seas are up, you may be beat or sea sick up just getting to the wreck, a wreck is more dynamic then a cave, it will change from day to day, month to month, etc. Caves will change from year to year if not much longer times.

For real wrecks first you battle the ocean and then the wreck.

 

[Beyond_Diving]

Conservation is indeed a big issue. Cave divers are trained from the start to have as little impact on the cave as possible, with perfect bouyancy, no contact, leave no marks, etc. There is a definite anbd agreed upon understanding in the cave community that caves take thousands if not millions of years to replace so what we have is all we are ever going to have.

There is some variance as some cave divers don't really give it the focus they should (IMHO). In N FL this September I saw some incredibly deep hand and gouge marks in what were recently flooded and fairly fresh cave floors. There are sadly way too many cave divers who skills frankly suck and should stay out of the cave environment until they improve, or care enough not to engage in what amounts to slob diving. (But to be fair, in the wreck community, no one would notice.) From a slightly different direction, In many caves where scooters are used, you can see shroud shaped gouges in the silt or clay on the floor and damage to the ceiling from tank impacts is common - as are many posts made by cave divers saying something to the effect "Me and my buddy were 4000' back in XXXX in a low bedding plane when he caromed off the ceiling and silted out the whole cave". (Not to bash all scooter divers, but the conservation ethics and expectations surrounding the practice in general could be improved - and oddly it is usually the buddy who screwed up, so I suspect there is at least some guilt over the damage.)

Unfortunately that is not an isolated event in FL. Last week I was getting ready to go into the water for a dive in Taj Mahal, and i saw a group of 3 divers coming up, and one of them had what looked like at least a 2' long chunk of stalactite wedged in between his tanks... when I confronted him about it, the guy and his buddies gave me an f you for an answer, and that's when I decided to descend before it escalated. Mind you, these weren't students. I've seen all 3 of them several times leading cavern tours (which leads me to believe that the cavern line is as far of a penetration as they've done in a long time - that is until that day).

 

[Gilldiver]

That seems to be a difference between east coast and west coast wreck divers. Back east, taking stuff seems to be the point of diving the wrecks. On this side, taking anything off the wreck is seriously frowned on, and can get you disinvited from the next dive ...

... Bob (Grateful Diver)

A lot of that is due to the type of bottom and condition of the wrecks on each coast. The East has much more shelf and a lot of sand, you have to go way out in most places north of Florida to get into 200+ feet. As a concequence, many of the wrecks were salvaged at the time of sinking, which means blown up to get to the engines, cargo, and non-ferrous metals, or are beat up quickly by current and storms. As a result many resemble a scrap yard more then a wrecked ship of the movies.

 

[TSandM]

One thing that hasn't been mentioned is disorientation. Wrecks are structures that are familiar, and your brain knows that a hallway is a hallway and a door is a door; if the wreck is lying at some weird angle to the bottom and you're inside it, your brain can keep trying to make it be the way it SHOULD be instead of the way it is (I speak from recent experience). This can be extremely disorienting.

A cave like the ones in Mexico, with decorations, will always orient you to up and down; caves also tend to do what they appear to be doing (at least in my limited experience of caves).

I know a fair number of people who dive both wrecks and caves, and almost no one seems to like both equally. You're either a cave person or a wreck person, I think. No doubt about which camp I fall into!

 

[Rhone Man]

Bubbles can also bring down the overhead. That can really ruin your day.

I have heard this said a lot, but have never actually heard of an instance of it happening. Are there any verified instances that people know of?

 

[DCBC]

It certainly seems that the OP has received lots of information. Great explanation by Cave Diver and others!

I would add another aspect that doesn't always exist, but may exist when cave diving and that is when diving in ocean caves (such as the Blue Holes of Andros), you have tidal exchanges that necessitate the dive to be undertaken within specific times of the day. Restrictions must be placed on penetration lengths (time) in addition to the concerns of mixture availability and decompression obligations. The tidal current may preclude a diver ever coming out alive if the dive plan is not correct and followed. The changes in the current during the dive may also complicate a safe egress. You don't have similar problems when you wreck dive.

 

[Rick Murchison]

Bubbles can bring down the overhead...

I have heard this said a lot, but have never actually heard of an instance of it happening. Are there any verified instances that people know of?

The team that attempted an exploration of the cave off the Lost Sea in Tennessee abandoned the project when their bubbles caused some very large rocks to fall from the cave overhead...
Once when entering a wreck off Pensacola, when my bubbles hit the overhead a solid layer of the world's biggest fire worms dislodged and came raining down on top of me. Set a record backing up that day.

Anyone have a regulator or any air integrated device freeflow while in an overhead environment?

Had it happen to a buddy. Nothing got dislodged in the overhead on that one, but we did shut it down quick.
Rick