Technical Diving and Salvage

[LM]

How necessary is a technical diving background when it comes to salvage, either professional or amateur?

[Jason in Enid]

Depends on how deep you want to recover from.

The term "technical" diving, while not set in stone, typically implies use of multiple gas mixes during a dive or use of rebreather equipment.

[VOC]

0 to 60 feet use air (cheap and safe, and as used by the majority of treasure divers).
60 to 110 feet use Nitrox if you can (safer if using air decompression tables or for extended bottom time if using Nitrox tables).
110 feet or more use (0pen circuit trimix or a closed circuit rebreather).
240 feet or deeper use a ROV (decompression of a bent diver gets really difficult if you have an incident at depth greater than this).


Best rule for treasure diving is keep your equipment as simple as possible and always very well maintained.

A lot of Technical Divers are only interested in the competitive side of diving (I’ve got more kit that you, I’ve got better kit than you, or I have dived deeper than you). This type of diver never makes a good treasure diver.

Working underwater requires a lot of hard work and concentration on the task in hand and you don’t want to spend all your dive monitoring meters and gauges, switching gases, and pressing buttons unless there is no other way.

Salvage diving of ships (raising ships as opposed to treasure salvage) is normally carried out by commercial salvage companies or professional diving companies and they will normally require all their divers to have been trained at a commercial diving school but any previous diving skills will be an advantage.

[cornelis 816]

The most important thing is that you recognize what you are looking at once you are below the water in the unfamiliar surroundings . Do you recognize the cannons if you see them . Do you see the difference in marine growth . Do you recognize the shape of a old wreck and what it has done to its surroundings . This is more important than tri-mix . Cornelius

[Salvor6]

NONE of the current professional salvors on the 1715 fleet have a technical diving background. Thats how necessary it is.

[stevemc]

Usually the only time it is used, is when a wreck is found by sidescan, in water too deep to dive it by normal air or Nitrox, and they need verification/provanance of the wreck before putting any more work into it. Then it might be used to work the wreck also. Usuallly Tech diving is used in deep caves, and water deeper than 180' feet deep for long periods, or anywhere that needs deep penetrations into a ships hull at those depths. The reason why it is not easily practical and common is all the cost of gases and equipment, and the maintainance of it, and the extremely long decompression times. I do know of quite a few shipwrecks that barney (Mike B) here on the board has verified. he has also been on the History Channel a few times doing so.