Divers are often confused between basic and advanced wreck diving certifications and why there is a need for two courses. This is a good question considering a wreck is a wreck and diving is diving. All wrecks present the same risks. The single biggest difference is the diver and what they want to do during their dive on the wreck.
Basic Wreck Diving
Basic wreck dives would consist of swimming around the outside of the wreck, with the occasional peek in the wheelhouse or cargo hold. That does not mean there is not a lot to learn, even though the plan is to stay on the outside, or that there is not a lot to see. For divers wishing to survey the wreck or watch the marine life it attracts, this is the perfect spot. The outside of a wreck is also where we get those dramatic photographs of the bow stabbing towards the surface, hoping to sail again. For the diver wishing to view a piece of history, diving on the wreck can show you what some will only read about or see in pictures. This type of wreck diving has been enjoyed by many and for some divers this is as close as they want to get to a wreck.
The equipment needed for a basic wreck dive is pretty much the same equipment used for any dive. There are some pieces of additional equipment that may come in handy: a large slate for drawing the wreck and noting depths and features, a small reel, and a lift bag or surface marker buoy (SMB) just in case you lose track of the anchor line or get blown off the wreck.
Advanced Wreck Diving
Advanced wreck diving is really an extension of basic wreck diving. Advanced wreck diving starts on the exterior with a survey that familiarizes the diver with how the wreck is oriented: on its keel, on its side, separated into halves or with a twist. No two wrecks are the same and all suffer different damages due to how they sunk, how long their journey was to the bottom or the severity of the storms that have battered them over the years. There are even vertical wrecks and wrecks clinging to the side of walls. Learning how to effectively survey the wreck is an extremely important part of any wreck course. This visual image, is the only thing the diver will have to rely on, since his compass will not work. Even wooden wrecks tend to have massive hunks of metal or boilers, which send the compass into a spin. But here is the point where advanced wreck diving waves goodbye to basic wreck diving; it is where we go beyond “the light zone.”
The light zone is where ambient light enters an overhead area and artificial light is required in order to see. Once a diver enters an area in a wreck where a light is required, the rules of wreck diving change. A diver in this area must have the knowledge and skills they need to go into and come out of a wreck should the worse possible scenario, a complete silt out, occur. In order to do this, divers must know how to use a reel for navigation and how to properly tie off lines so they will not get cut during the dive. But this is also where the fun starts for wreck divers craving to study the more intimate details of the wreck or seeking that hidden artifact that no one else has seen.
Many wreck divers don’t feel they know all there is to know about a wreck until they have explored every room, seen the engines that pushed this once mighty vessel through thousands of nautical miles. There are also those who want to see the artifacts, some still lying in place as if the ship had never sunk. To some, the best part of the wreck dive started before they even entered the water, it was the hours of researching and planning that lead up to the dive. But before a wreck diver can see these sights they need to undergo serious dive training and have an experienced TDI Wreck Instructor explain the safety protocols. Remember that worst case scenario of silting out? For divers who spend their time on the outside of a wreck, this silt would only come from the fin thrust as it hits the bottom or deck of the boat. For divers entering the wreck, this silt comes from above and is called percolation silt, cased by the exhaled bubbles as they dislodge rust, insulation or other debris trapped on the ceiling.
Another big area of difference between basic and advanced wreck diving is the equipment needed. Advanced wreck divers should carry at a minimum two lights a primary and a back-up, two cutting devices, two reels, two lift bags and a redundant air supply. While this may sound like a lot of equipment, a TDI Advanced Wreck Instructor can teach divers where to stow this equipment and still keep very streamlined in the water.
Wrecks have a mysterious calling to many people. Wrecks that occurred due to war or sank because of a violent storm draw divers in, some say this is because it closes that chapter in our lives. Others would go there because they read about it in history books and they wanted to see it firsthand. Whatever the reason, or if you are going to view the wreck from the outside or inside, it is always best to take the course from an instructor who has been there and done it. Sometimes the best lesson learned from a course is not what is in the book or the skills you had to perform, it is merely what you learned by diving with and watching how an experienced instructor handled himself underwater.
Every wreck has a story, even the ones that were sunk intentionally. So do yourself a favor…find out what that story is! Safe diving!