Penetrating Questions
When diving a wreck, should you go inside? Not without proper training.
Whether it's a historic vessel lost to the indignities of war and weather, or an everyday
freighter sunk as a diver's playground, there's something about wreck diving that gets a
diver's blood bubbling--in a good way. It can also be one of the most dangerous pursuits in
diving, especially when divers penetrate a wreck's interior without proper training and gear.
Open Water Wreck Diving
The first step to safely diving wrecks is entry-level wreck diving certification. Offered by
recreational training agencies, this course teaches you to identify and deal with common
hazards found when diving the exterior of a shipwreck. These hazards include
disorientation, sharp metal edges and entanglement hazards created by rigging, nets and
monofilament line.
In addition to making exterior explorations safer, an entry-level wreck diving course is also a
good first step to advanced levels of wreck diving. Your training dives in an open-water
wreck diving course focus on surveying the wreck to identify all potential hazards and
proper navigation techniques to help you maintain a constant awareness of your position
on the wreck relative to the ascent line. The metal in the shipwreck can make your
compass virtually useless for navigating, so this part of the class focuses on natural
navigation cues.
Limited Penetration
The next level of training teaches skills for limited penetration. Limited-penetration divers
typically use traditional recreational equipment, although some also carry a wreck reel for
primary navigation. While limited-penetration courses are offered by most recreational and
technical training agencies, the definition of limited penetration is not clear-cut. Most
technical agencies define limited penetration as swimming into simple swim-through
areas where the risk of entanglement and entrapment is minimal and the diver can remain
inside the natural light zone created by the entry area. Limited-penetration divers should
never rely on light streaming through portholes or other nonpassable openings and should
always keep the entry/exit point in easy view.
The biggest potential hazard for the limited-penetration diver is loss of vision. The clear
water inside the wreck will nearly always be clouded by rust particles, silt and other
sediments when you turn to exit. Poor buoyancy control, poor fin technique and even your
exhaust bubbles will cause this diminished visibility by kicking up sand and silt, and
dislodging sediments from rusting steel plates overhead.
These clouds of silt and sediment can range from a minor annoyance to a disorienting
hazard that completely robs you of the ability to see. To alleviate these problems,
limited-penetration divers are trained to penetrate only open passages that have large
openings for access and preferably more than one opening for entry and exit.
When diving a wreck, should you go inside? Not without proper training.
Whether it's a historic vessel lost to the indignities of war and weather, or an everyday
freighter sunk as a diver's playground, there's something about wreck diving that gets a
diver's blood bubbling--in a good way. It can also be one of the most dangerous pursuits in
diving, especially when divers penetrate a wreck's interior without proper training and gear.
Open Water Wreck Diving
The first step to safely diving wrecks is entry-level wreck diving certification. Offered by
recreational training agencies, this course teaches you to identify and deal with common
hazards found when diving the exterior of a shipwreck. These hazards include
disorientation, sharp metal edges and entanglement hazards created by rigging, nets and
monofilament line.
In addition to making exterior explorations safer, an entry-level wreck diving course is also a
good first step to advanced levels of wreck diving. Your training dives in an open-water
wreck diving course focus on surveying the wreck to identify all potential hazards and
proper navigation techniques to help you maintain a constant awareness of your position
on the wreck relative to the ascent line. The metal in the shipwreck can make your
compass virtually useless for navigating, so this part of the class focuses on natural
navigation cues.
Limited Penetration
The next level of training teaches skills for limited penetration. Limited-penetration divers
typically use traditional recreational equipment, although some also carry a wreck reel for
primary navigation. While limited-penetration courses are offered by most recreational and
technical training agencies, the definition of limited penetration is not clear-cut. Most
technical agencies define limited penetration as swimming into simple swim-through
areas where the risk of entanglement and entrapment is minimal and the diver can remain
inside the natural light zone created by the entry area. Limited-penetration divers should
never rely on light streaming through portholes or other nonpassable openings and should
always keep the entry/exit point in easy view.
The biggest potential hazard for the limited-penetration diver is loss of vision. The clear
water inside the wreck will nearly always be clouded by rust particles, silt and other
sediments when you turn to exit. Poor buoyancy control, poor fin technique and even your
exhaust bubbles will cause this diminished visibility by kicking up sand and silt, and
dislodging sediments from rusting steel plates overhead.
These clouds of silt and sediment can range from a minor annoyance to a disorienting
hazard that completely robs you of the ability to see. To alleviate these problems,
limited-penetration divers are trained to penetrate only open passages that have large
openings for access and preferably more than one opening for entry and exit.
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All About Florida
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Full Penetration
The most advanced form of wreck diving is full-penetration or
technical wreck diving. At this level, divers are trained to penetrate
to any level of the ship provided that the structure is stable and
the dive is within the skill and experience level of the diver.
The penetration diver must have skills very similar to those used
in cave diving, and he assumes that every wreck dive will be a
decompression dive. Therefore, most training programs go
beyond penetration skill to include gas management techniques
and the use of decompression gases to facilitate staged
decompression stops during the ascent. This training often
includes use of a lift bag or surface marker to allow the dive boat
to track the diver's location if he is forced to decompress while
drifting. In addition to a stage tank and a surface marker, the
penetration diver will replace his primary cylinder with either a
high-capacity (98 to 120 cubic feet) single cylinder with an H valve
or a twin cylinder configuration utilizing an isolation manifold with
two regulator connection outlets. Either of these tank
configurations will allow the diver to both carry more gas and to
carry a complete, separate regulator system consisting of a first
stage and second stage connected by a five- to seven-foot-long
hose.
If the diver should find himself inside the wreck and experience a
catastrophic failure in one regulator system (such as an
uncontrolled second stage free flow), the diver can simply shut
down the malfunctioning regulator and switch to the backup. This
will allow the diver to preserve his gas supply for exiting the wreck
without having to share gas with a buddy. If the situation
becomes even worse and the diver finds his primary gas supply
completely exhausted, the seven-foot hose allows the diver's
buddy to share gas even if the divers have to pass through
restricted passageways one behind the other. Penetration divers
also use a conservative gas management technique called the
rule of thirds. In very simple terms, this means that the diver uses
one-third of his gas as he swims away from the exit point,
one-third of his gas to return to the exit point, and saves one-third
of his gas to deal with any emergencies that may occur.
The full-penetration diver will use wreck reels and line markers to
safely navigate inside the wreck. During the course of
penetration, the divers will survey the structure of the wreck to
look for loose or unstable structures and alternative paths to
open water should the primary entry route become impassable.
Technical wreck dives can be done on any intact structure;
however, divers pursuing this passion frequently discover that
deeper wrecks offer the most potential. Therefore, most technical
wreck divers will also get training in extended-range or tri-mix
diving in order to access wrecks in the 150- to 330-foot range.
The most advanced form of wreck diving is full-penetration or
technical wreck diving. At this level, divers are trained to penetrate
to any level of the ship provided that the structure is stable and
the dive is within the skill and experience level of the diver.
The penetration diver must have skills very similar to those used
in cave diving, and he assumes that every wreck dive will be a
decompression dive. Therefore, most training programs go
beyond penetration skill to include gas management techniques
and the use of decompression gases to facilitate staged
decompression stops during the ascent. This training often
includes use of a lift bag or surface marker to allow the dive boat
to track the diver's location if he is forced to decompress while
drifting. In addition to a stage tank and a surface marker, the
penetration diver will replace his primary cylinder with either a
high-capacity (98 to 120 cubic feet) single cylinder with an H valve
or a twin cylinder configuration utilizing an isolation manifold with
two regulator connection outlets. Either of these tank
configurations will allow the diver to both carry more gas and to
carry a complete, separate regulator system consisting of a first
stage and second stage connected by a five- to seven-foot-long
hose.
If the diver should find himself inside the wreck and experience a
catastrophic failure in one regulator system (such as an
uncontrolled second stage free flow), the diver can simply shut
down the malfunctioning regulator and switch to the backup. This
will allow the diver to preserve his gas supply for exiting the wreck
without having to share gas with a buddy. If the situation
becomes even worse and the diver finds his primary gas supply
completely exhausted, the seven-foot hose allows the diver's
buddy to share gas even if the divers have to pass through
restricted passageways one behind the other. Penetration divers
also use a conservative gas management technique called the
rule of thirds. In very simple terms, this means that the diver uses
one-third of his gas as he swims away from the exit point,
one-third of his gas to return to the exit point, and saves one-third
of his gas to deal with any emergencies that may occur.
The full-penetration diver will use wreck reels and line markers to
safely navigate inside the wreck. During the course of
penetration, the divers will survey the structure of the wreck to
look for loose or unstable structures and alternative paths to
open water should the primary entry route become impassable.
Technical wreck dives can be done on any intact structure;
however, divers pursuing this passion frequently discover that
deeper wrecks offer the most potential. Therefore, most technical
wreck divers will also get training in extended-range or tri-mix
diving in order to access wrecks in the 150- to 330-foot range.