Types of Metal Detecting Activities, page 30:
SHIPWRECK DIVING: Scuba Gear for Underwater Treasure Hunting
• Mask
Any mask that fits properly is perfectly suitable for wreck diving. The prescription masks now also available over the counter at almost all dive shops.
If there is a possibility for the mask to be ripped off by the wave or dive entry, it is advisable to wear the mask strap inside your wet or dry suit hood. The mask should have a nose pocket, so you can pinch your nose for clearing your ears.
The lenses should be made from tempered glass and the volume of the mask must be small enough to make clearing the mask easy. The strap clip should be sturdy enough to last the lifetime of the mask, and you should be able to change the strap without difficulty.
• Fins
Like shoes they should fit you well. They should not move on your feet when. There are two basic types of fins: slipper-style fins (pool fins), which fit on bare feet and are useful for those who want to snorkel or do pool training. Strap or Drysuit type fins are worn over diving suit boots and should be bought to fit the type boot on your suit.
Adding a pull tab onto the strap of each fin will make it easier to to put on or take off your fins if you wear heavy gloves or mitts while treasure hunting in cold waters. This pull tab can be made from a small piece of nylon belt material sewn into a loop over the fin strap, or bought in any dive shop.
• Dry Suit
The type of drysuit (neoprene or membrane) you pick should be comfortable and give a full range of movement: you should be able to lift your leg high enough to put your foot on top of a chair with your arms lifted above your head. Membrane suits are generally more "baggy" than neoprene suits to allow for the undersuit, which can result in greater drag in the water. These suits are the most popular because of their flexibility.
Some drysuits have hoods attached. If not, you should have a hood that fits your head. If water can enter and leave the hood, it will cool you head and cool you down. The face seal should fit neatly, and the neck opening should extend over the neck seal on the drysuit. It is also a good idea to have a reflective panel on the top.
• Gloves and Mitts
Neoprene gloves that have a kevlar coating are better suited to shipwreck and shore diving, as they will last a lot longer. Make sure the kevlar covers the whole glove not just the finger tips. Other gloves are warmer due to special linings or are dry due to seals on the cuffs.
Dry gloves may have a furry lining and can have a special connection to the suit. These are expensive and not for wreck or shore diving. These gloves tend to be used in extreme cold water like ice diving.
For easy putting on your gloves, you can use a pair of plastic gloves under the dive gloves. Remember that you should be able to access all the clips and controls on your dive kit while wearing your gloves.
To increase their life, shipwreck divers use a thin coat of aqua seal glue on the finger tip area of each glove. But if you apply too much glue, you will lose dexterity to the stiff hardening substance.
Mitts are used for diving in cold water and have three fingers instead of five. They are less dexterous but much easier to get on and off.
Scuba Diving Gear
• Scuba Tank (Compressed Air Cylinder)
The size of cylinder you require depends on your SAC (surface air consumption) and the type of diving you will be doing. There are tall thin and dumpy cylinders. It is a good idea to have a pony cylinder as a completely separate gas supply.
• BCD (Buoyancy Compensating Device)
The BCD is used to float the diver and equipment on the surface and allows for adjusting neutral buoyancy at depth. Cold water diving calls for the use of drysuits and extra weight, both of which require more lead to offset the extra buoyancy. In contrast, warm water diving requires that a BCD have little more than tank bands and a place to hang your hoses and enough lift to float the diver with minimal weight.
Standard stabilizer jackets or buoyancy compensating devices (Stabi or BCD's) provide buoyancy around the back, under the arms and over the shoulders. Many BCD's offer integrated systems which allow the diver to use a weight system to store weights as part of the BCD which includes the ability to be able to ditch the weights in an emergency. The weights are put in a pouch and slide in a pocket of the BCD and are attached directly to the BCD by velcro.
• Regulator
To reduce the chance of a snag, make sure that your regulator hoses are streamlined: route all hoses as close to your body as possible. Depending on the regulator model, this may require the use of wire ties or velcro straps.
• Pony Bottle, Octopus or a Double Tank System with twin regulators
One of these is your alternate air source and should be mounted in a convenient and easily reached, secure location. The best way is to secure the regulator's second stage to a loop of surgical tubing worn around your neck, so you would not have to search around for your alternate air source because it is always directly under your chin.
• Multilevel Dive Computer
Such meters should be in bold digital numbers telling you exactly where you are and how much if any decompression is needed; all information should be digital. The dive computer is also an excellent and extremely accurate bottom timer and depth recorder.
• Bottom Timer
Two bottom timers are mandatory for exploring the deep shipwrecks. Bottom timers can be mounted on your wrist or even strapped to the deflator hose of a buoyancy compensator, or they could be part of another gauge or decompression meter just as long as they are accurate, easy to locate and read.
• Gauge Console
By utilizing a gauge console, you can quickly scan all of your gauges at one time. Consoles range from small two gauge units to rigs that hold five or six gauges. It is a good idea to have a depth and contents gauge on the console as the depth gauge is a good backup for your dive computer.
• Decompression Tables
Decompression tables protected in a dry housing and installed inside a clear dive light housing will allow you to easily read them while underwater without fumbling around while looking for them in a buoyancy compensator pocket.
• Weight Belt
Two buckles should be installed to your weight belt to prevent getting plastered to the shipwreck’s ceiling when the weight belt is dropped in emergency while inside a ship. Only expendable items should be attached to a weight belt.
• Weights
Lead weights come in various weights, shapes and sizes and can be coated in plastic. They can be added to a Standard Webbing Belt which wraps around the divers waist, to a Pouch Belt, or to a Harness system. Dive weights can be of the following types: Integrated Weights, Trim Weights, V Weights, and Back Plate Weight (a cross between the V weight and the Lead Shot Pouch). Carrying more weight than necessary can lead to diver’s stress, increased air consumption and difficulty in controlling buoyancy.
• Ankle Weights are worn with dry suits to reduce buoyancy in the foot area; thus, allowing for easier swimming and more comfortable diving. Ankle weights are fastened around the ankle of the diver with pinch clips.
• Harness
The harness is worn over the shoulders and around the waist of the diver. Most harnesses provide secure D-Rings for attaching lights, reels and tools.
• Velcro Double Bands
The velcro double bands allow for easy replacing and removing tanks, one tank at a time, and pony bottles.
• Pony clamps
There are four principal ways of securing the pony cylinder to the main rig: within a fabric sack, by means of a metal clamp system, using cam band straps, and by side mounting.
• SMB (surface marker buoy) or DSMB (delayed surface marker buoy)
The delayed surface marker buoy and surface marker buoy can be used to show the position of a diver, provide a support from which to hold while being in a stop for safety or stage decompression. It can also be used as a sign for boat traffic in general and a means of predetermined signal communication. Shipwreck divers use either a red/orange color for standard routine use or a yellow color to indicate a problem.
• Reels
There are three main types of reels: gap reels, ratchet reels and finger spools. For safety reasons, you should never deploy your SMB (surface marker buoy) with the reel attached to yourself.
• Piston Clips
Piston clips are the preferred method of connecting things when diving. Double ended piston clips have the added security if one side gets stuck you can use the other end. Piston clips made of stainless steel are superior as they do not jam as much as the brass.
• Wrist Lanyard
A wrist lanyard is handy for connecting you torch to your wrist so you can drop it in an emergency without loosing it. They are also handy as a backup for an expensive dive computer.
• Loop Shock Line
Loop shock lines are generally used for torches and cameras. One end is connected to a D-ring on your BCD, and the other end is connected to the torch. When you need to use the torch, squeeze the pinch clips in the middle, and the shock line lets you use it but not loose it.
• Pinch Clips
Pinch clips as used on your BCD for shoulder, chest and waist connections. They can be used on lanyards for connecting torches and DSMB's to your BCD.
• Hose Holder
Hose holder attaches the clip to the BCD and the contents gauge or octopus hose.
• Snoopy loops
Snoopy loops are made by carefully cutting a car inner tube into loops approximately 10-20 millimeters wide. They have many uses such as holding second stage hoses on sideslings, laying lines in shipwreck diving, etc.
• D-rings
D-rings are on every BCD to hang your torch or DSMB, or on shot weight belts to attach a jon line.
• Billy rings
Billy rings are used for simple attachment of side mount stage cylinders and other accessories.
• O-Rings
O-rings made out of silicone have a longer life and are more durable than o-rings made of rubber.
