Category Archives: Recreational Gear

NAUI Advanced Scuba Diver

 Class Structure

The class consists of one classroom session and six dives in open water.

All participants should be a minimum 15 years old and a NAUI Scuba Diver or equivalent. Divers should have recent experience in similar conditions to their training, and have all gear serviced in its normal maintenance period as specified by the manufacturer.

Equipment

To participate in the NAUI Advanced Scuba Diver course, each diver must have access to scuba diving equipment, either rented or owned. Any equipment that is not rented must be approved for use by the Instructor, and be serviced within the past two years for buoyancy compensators (BCs) or regulators.

Special additional equipment that is needed is a cutting device, flashlight and cylinder light.

Gear considerations

Every piece of equipment that is taken diving should be make specially for diving. Repurposed general equipment is typically not waterproof, corrodes easily in marine environments, can be difficult to attach or to use underwater with thick gloves.

You should always label your dive gear with some identifying mark. It is likely that you will lose some piece of equipment at some point, and the chances of it being recovered and returned to you are much improved. Labelled gear makes it much easier to identify your own gear on a boat or gear wash tub.

All gear should be streamlined on the divers rig. Consider where it would be attached to the diver so that is does not dangle and impose an entanglement hazard or a risk to precious formations like stalactites or corals.

Pay attention to how well the devices can be attached to your gear, and how secure they are in sheath. You don’t want to lose a poorly attached piece of equipment in rough surf, and you need to be able to reach and deploy it on the surface or underwater in a trim or vertical position. The addition of full gear for an actual dive can greatly change the accessibility of gear when you add weight pockets, other devices or tighten straps down for diving. Would you still be able to reach your gear in an entanglement?

Most scuba BCs are constructed with 1″ or 2″ width webbing for the straps. It is helpful to know the construction of your BC. If in doubt, take your gear to the shop to try various configurations before you buy.

Carry spare batteries in your save-a-dive kit so that you are not affected by a failure before or between dives. Check all your gear in your pre-dive checks that it is present, deployable and working.

Cutting device

The cutting device is used to remove entanglements like kelp or fishing line, and for removing a diver’s buoyancy compensator straps or wetsuit in an emergency. Only one cutting device is required and should be in an accessible location. Typical locations on the waist strap or BC inflator hose. Many BCs have attachment points on the integrated weight pockets.

DeviceMounting PointAdvantagesDisadvantages
Dive KnifeWaist strap, inflator hose, computer wrist strap, inner calf.Can have a sharp or blunted tip to prevent accidental puncture of the BC, Mounting location should consider ease of sheathing underwater after deployment.
ScissorsWaist strap, inflator hose.Prevents accidental cuts and punctures, easy to safely remove a wetsuit from a victim, useful as a general tool.Bulky.
EZ CutWrist computer strap, waist strap, inflator hose.Easy to deploy and sheath, prevents accidental cutting, velcro system prevents loss, small and easy to carry multiple devices.Blades need to be occasionally replaced due to corrosion (comes with spare blades).

 

 

A safety knife with sheath.

A safety knife is small and streamlined, and easy to use underwater. The protected blades prevent accidents and velcro on the tab keeps is secure in the pouch. The pouch should fit most 2″ webbing.

Dive scissors with sheath.

Although bulky, scissors are easy and safe to use on land an underwater. They can be convenient for dive rescues when a diver needs to be removed from an exposure suit quickly or without aggravating a neck or spinal injury due to the bent blades.

A small dive knife with serrated edge, line cutter on spine and stubbed tip.

A titanium technical-style dive knife with velcro pouch.

Dive knives vary in size, can can have a straight or serrated edge, a notched line cutter, and a pointed or blunted tip. Small dive knives are usually sufficient. Technical-style knives are tyipcally thin and light for streamlining and reducing additional weight. Some knives are titanium so they do not corrode. The pouch should be tested to ensure the knife is well secured to prevent loss.

Dive lights

Most modern dive lights are LED due to their high intensities, long burn time and small size. Lights can be rated by number of Watts (amount of power consumed), lumens (total light output) or lux (density of light per square foot). They are not directly comparable without knowing a lot about the LED bulb(s) and the geometry of the output light beam. However, many manufacturers have settled on lumens.

Divers considering specialized forms of diving in the future, like cave or wreck, or decompression diving should consider equipment appropriate for technical diving. For example, a primary dive light for recreational diving that can be used as a backup light in technical diving.

Lights, more than other equipment, can be very bulky and hang precariously from a divers body when stowed. It is advantageous to have be hands free by using a hard goodman handle, or a short leash for securing the light to the body.

Considerations for a dive light should include sufficient burn time for the intended dives, e.g. 1–2 hours, and the type of beam. Flood lights are undesirable unless using as a video light to illuminate a scene because they can easily blind dive buddies. A narrow beam of 10–15 degrees is good for creating an intense spot for communication, with a wider spill area that is less intense.

A magnetic switch on lights prevents underwater flooding. Lights that use a twist action to turn the light on or off should be double o-ringed for additional flood protection. All lights should have a means to closely attach to the divers gear when not deployed.

Light options are discussed on the Technical Gear page.

Cylinder lights

Cylinder lights are used so that you can easily locate your buddy, especially if their primary light fails, or if they are partially obstructed. If it is possible different colors can designate teams or buddy pairs if multiple teams are in the water at the same time. Cylinder lights are often a requirement in dive tours when a guide is responsible for a large group of divers. Chemical lights are mounted around the neck of the cylinder or the BC cylinder band so they float above the diver or behind their head when in the water.

An LED cylinder light.

LED cylinder lights could be a fixed color, or have multiple colors that can be chosen at the start of the dive. Batteries typically last many dives before needing to be replaced.

A disposable chemical cylinder light.

Disposable chemical lights are single use, and work like typical glow sticks where a glass chamber is broken to activate the chemical compound. One use typically lasts multiple dives. For limited use they are the cheapest option, but contribute to plastic waste.