A light and a knife are the first two non-essential accessories that you should get. Actually, neither one is non-essential, and only a fool would dive around here without both. Goody bags are used to carry booty from the sea. This includes fish, shellfish, and treasure. They can also be used to carry tools down with you.
8-D-cell light with lantern grip
In the murky waters off New Jersey, you are going to need a powerful dive light if it is to be of any real usefulness. There are many different types of underwater lights to choose from.
Standard incandescent bulbs are the least efficient in terms of light output, but they are also the cheapest, and replacement bulbs are easily available. Some lights use dual bulbs or dual-filament bulbs for redundancy. This is not a bad thing. In my experience, most incandescent bulbs die unnatural deaths when the hot filament breaks after the light is dropped, rather than burning out from use. Always keep extra bulbs on hand.
Incandescent lights throw a yellowish beam. Halogens are whiter and brighter, but more costly. LED lights are dim, but do not burn out like regular light bulbs, making them a good choice for backups. HID lights are ghastly expensive, but throw an extremely bright white light that looks almost purple underwater. They also have a much better burn time than incandescents. A light this bright is likely to leave you blind in the dark if you turn it off. I am always annoyed when another diver comes around with a blinding bright HID light.
Beam pattern is probably more important than brightness, Your main light should throw a wide beam, for area illumination. Many lights throw a narrow pencil beam that appears to be brighter, but is actually less useful. These are best used as backups and in special situations, such as camera strobe aimers. Some lights are adjustable.
Small lights may have no handle at all, you simply grasp the body. This is a poor option for a main light, as it completely occupies that hand, making two-handed tasks difficult. Most larger lights have pistol grips. These may look neat, but again this is not a good solution, as it places the hand in an awkward position for doing anything else. Canister-type lights with separate corded light-heads are typically used with a "Goodman" handle (above) which supposedly frees the hand for other tasks, but in fact does pretty much the opposite - any attempt to use the hand is likely to point the light off in a strange direction. Not only is the hand completely encumbered, but you need your other hand to free it, as opposed to simply letting go of the light.
Horizontal lantern-type handles are the best. With a lantern handle you can hold the light in a useful position, and hold and use something else ( such as a wreck reel or a spear ) in the same hand, something that is simply impossible with a pistol grip or Goodman handle.
Battery options range from standard disposable cells to specialized rechargeables. Cave divers use large brick-type rechargeable batteries, housed in waterproof canisters that are worn on the back. The fact is, wreck divers do not need 16 hours of continuous burn time, and this is complete overkill, at a very high price. Another problem with this setup is that the corded light heads, whether incandescent, halogen, or HID, are fragile. I have seen so many of these things get broken on the boat, before they even hit the water, and many more come back from a dive broken. I would not buy one - leave them for the cave divers.
The best choice in batteries is standard D-cells. Go to Radio Shack, and pick up a set of rechargeable NiMH or NiCd batteries and a charger, if you don't already have one. This will give you a rechargeable light with a disposable battery fallback if it is ever necessary. This is much better, cheaper, and more flexible than buying a factory rechargeable light. Note: rechargeable D-cells are often just C-cells in bigger casings, so if you plan to do this, a C-cell light may be just as good. One charge will typically last for three dives.
8 cells is better than 4 because an 8-cell light will sit flat when you set it down, and point where you want it to. Whether you are hunting lobsters or bottles, this feature alone is worth the extra cost over a smaller light. Also, battery and bulb life in the 8-cell lights is much better than in the 4-cell ones, which means less chance of being left in the dark during a dive.
One drawback of rechargeable batteries is that they weigh less than alkalines, and your light may become positively buoyant. This can be very annoying, because your light will hang up instead of down. To remedy this, glue a couple of ounces of lead weights inside the back of the reflector. Split shot and silicone adhesive work fine. Rechargeable batteries are also lower voltage than disposables - usually 1.2 volts vs 1.5 volts. This means your light will be not quite as bright ( with 8 cells, it amounts to 2.4 volts, or 20% ) but also that the bulb will last longer.
It's no accident that I placed a picture of a Pelican Aqua King light at the top of this article. It has all the qualities I consider good in a main light: lantern grip, 8 D-cells for power ( I use rechargeable NiCds ), wide even adjustable light pattern, and a dual filament bulb. It's not the brightest or smallest light you can buy, but it is tough, reliable, easy to use, and relatively inexpensive.
The fact is, you do not need a super-bright light underwater, nor do you need a massive burn-time. With experience, you will find that using the ambient light around you gives you a much wider and better view of your surroundings - the big picture - except of course for the colors. Constantly using a dive light gives you a very narrow view of the world, and following the beam of your light is no way to navigate. Such divers are much more prone to become disoriented and lost. It also scares away much of the marine life. Keep your light turned off most of the time, and use it just to look into dark corners, while trying not to ruin your dark vision. Used like this, I recharge my light about once a month !
Get rid of the wrist lanyard on your light, and make up a much more useful rig like this. And remember, most dive lights are not meant to be used for extended periods out of the water - they may overheat and melt.
The DIR-recommended primary light is a back-mounted battery canister, with Goodman-handled light head. I've spent several paragraphs tearing-apart such setups, and I won't repeat myself.
A dive knife should also be considered standard equipment, since many dive locations have hazardous monofilament in which you can become entangled. Don't skimp on your knife either - the most commonly found artifact off the New Jersey coast is the cheap dive knife that has slipped from its sheath. When looking at knives in the store, scrutinize the locking mechanism and the sheath. Is it secure and unlikely to release by itself, yet also easy to use? Will it loosen under use, or break with age? Tug at it, and try to see if you can work it loose without actually hitting the release. If you can, then don't buy it. Also, bigger is not necessarily better - many of the best knives on the market are only 10 inches long overall.
Some other features to look for in a knife are:
Some knives only fit into their sheaths one way, that is to say they have a right side and a wrong side. These are non-starters as far as I am concerned. The knife should lock firmly into its sheath no matter how it is inserted, and you should be able to get it in and out by feel alone, without looking.
A small spare emergency knife is also a prudent thing to carry. I carry a small stainless steel folding knife in my BC pocket, where it is out of the way unless I need it. This particular knife even has a quick release lanyard to prevent it from getting lost from an open pocket. You can get a similar knife at Sports Authority for about $25.
The one thing that a dive knife does not need to be is particularly sharp or pointy. For line cutting, the saw teeth on the back of the blade are far more useful than the edge. ( That little line-cutter notch that every manufacturer includes is totally useless. ) If your knife is very sharp and pointy, it will just be that much more dangerous to put back in its sheath on your leg. The ocean will quickly corrode the fine edge off a steel blade anyway.
Tropical divers may get away with wearing their knife on an arm, BC strap, or thigh, but really the best place for a knife is inside the right calf at about 10 o'clock ( lefties - mirror image. ) This location is easily reachable by simply bending the leg, and there is nothing to obstruct removing or replacing the knife in its sheath, and the operation can be performed with one hand. Most importantly, though, on the inside of the leg the knife is far less prone to snags and entanglements in the water. A sure sign of a freshly minted diver is a huge new knife strapped proudly to the outside of the leg. Some divers keep a knife on their gauge console. This is fine for a small spare, but I would not mount my primary knife this way as it might require both hands to get it out.
On most dives I find that I never even touch my knife. Needlessly fiddling with it in the water is just a good way to lose it.
My favorite knife is the Seaquest Z-Lock type, shown above. This knife has all the desirable features described, as well as a very compact streamlined sheath. The blunt-tipped models should be avoided, though. These are made from extremely hard "440" steel, so that they can take a very good edge if you know how to sharpen them. However, this hard steel is also brittle, and I had one snap off like a wine glass after a low fall. Seaquest replaced it right away with a pointed model, as I requested, since the pointed model is made from milder "300" steel. Not quite as sharp, but a lot tougher - it will bend rather than break. This is important if you ever want to use it as a pry bar ( not recommended. )
You can read in the dive magazines how these are the greatest thing ... cut through stuff that a knife won't ... blah blah blah. Don't believe it. These lightweight, essentially disposable shears are designed for very limited medical uses - cutting through bandages and similar materials. Sure, you can cut a penny in half with a brand-new pair, but how often is that going to be useful during a dive? They are not and never were designed to cut through tough nylon rope, netting, and many of the other entanglements you might find underwater. The one thing that these shears can cut reasonably well is monofilament, but you can usually just break out of that by pulling on it.
Sea Snips also don't hold up very well. While the blades are more or less rust-proof, the little rivet that holds them together is not, and after a few dives it will be considerably weakened by corrosion. The result is that if you ever have to actually use your "Sea Snips", they will probably break in your hands. If you are already in an emergency situation, this will make it worse. Using them with thick gloves or mitts may be an issue as well, especially compared to just pulling out a knife.
Some folks say Sea Snips are a useful adjunct to a knife. I say they are just an extra piece of junk to get in your way. Don't waste your money. If you must have a pair of Sea Snips, do yourself a favor and drill out the rivet and replace it with a stainless steel bolt and locking nut.
The recommended DIR cutting tool is a sawed-off 1/2 -inch stub of a kitchen knife. This boggles the mind to the point that I had to go and get a picture of one - see at right. I cannot imagine how this lame contraption would be useful in open water. For God's sake, get a real knife.
( In fairness, DIR-F does not recommended this silly thing for open-water use. )
Goody bags come in several lengths and sizes, but three feet ( yellow mesh ) is by far the handiest and most popular size. Bigger bags are too much of an encumbrance, and if filled to capacity, say with mussels, become too heavy to safely carry underwater.
Goody bags come in a variety of materials. Open nylon mesh is the most common, and drains instantly when you exit the water. It is also the best for dragging mussels behind the boat. Canvas is good for spearfishing, as it keeps the fish slime off you, yet still drains reasonably well. It can also have a calming effect on your prey, resulting in less thrashing about. Of course, with a canvas bag it is more difficult to admire your catch during your hang at the end of the dive. Nylon cloth is used for small tool bags. It is the strongest of all, but drains very poorly. A large nylon bag full of water is a very heavy load to drag up a dive boat ladder.
The first thing to do with a goody bag is attach a brass snap to it with nylon line. The base of the snap should be attached to the frame of the bag, which is much stronger than the handle. It might be better to attach the brass snap to the bag material instead, to avoid the galvanic reaction of dissimilar metals in contact, which will cause the bag frame to rust faster.
A three foot goody bag flowing out behind you can be a real tangle problem. The usual way of stowing it is to open it up and throw it inside of itself. Take a lobster gauge and tie it onto the bag frame outboard from the handle with a foot or so of wreck line. This way you can have it in or out of the bag and use it, but not lose it.
If your goody bag gets a fishy stink, rinse it out well, and hang it out in the sun for a few days.
Since you are not supposed to touch anything underwater, there is no need for a DIR goody bag. It would be an entanglement hazard anyway.