Dive-kit

For most of us we don’t get the opportunity to scuba dive every day. When you get the time or opportunity to go scuba diving, you want to make sure you have a great day in the water. You spend time to get to your dive location, then find a broken piece of equipment – great day of scuba diving is destroyed. Add a save a dive kit to your dive bag to prevent this from happening to you. You cannot prevent all equipment failures you can make sure you are prepared when failures inevitably occur.

Experts say it is important to have the repair essentials in your dive bag to be ready for the unexpected. The last thing any of us want is to miss a great day diving because of failed equipment. After spending your time and hard earned money nothing is worse than having to sit out of a dive because of a broken strap.

Preparedness for a day out scuba diving starts with an inspection of your equipment. Even before you leave for your dive or trip pull out all of your equipment. Give your scuba dive gear a thorough inspection. Look for any torn or worn out components. Straps, mouthpieces, snaps are all items that take a lot of abuse and need regular replacement.

Check your o-rings! O-rings are replaceable parts, designed to replace regularly. O-rings are one of the most common failure points. Quick and easy to replace, make sure your dive bag has a supply of the most common sizes – these will save your dive. Check out this article for a lot more about O-rings.

Finally, tools – make sure you have tools in your save-a-dive kit. Critical tools include, screwdrivers, wrenches, pliers and picks. A few simple tools or a rust-resistant multi-tool are super handy and will definitely be useful in saving a dive.

What is an O-Ring and Why is it Important to Scuba Diving?

An o-ring is a circular shaped gasket used to seal two working surfaces together. In scuba diving the o-ring is a critical part to making your equipment operate safely allow for you to dive without worry. O-rings are not created equal! There are a number of differences in material, hardness, and size that are very important to understand. Picking the wrong type of o-ring for your dive kit can lead to failure under pressure. Additionally over time because of the nature of material used to make o-rings they dry out and develop cracks over time. Which is why it is important to check and replace your o-rings at regular intervals and be ready with a fresh supply of o-rings in your save-a-dive kit. Also don’t forget to replace your save-a-dive kit supply of o-rings every few years to prevent additional failures and lost dives!

What are the Common O-Ring Material Types for Scuba Diving?

The most common types of o-rings used for scuba diving are made of various materials. Below is a list of the most common scuba o-ring materials.

FKM / FPM / Viton   – Viton is a trade name of Dupont but these Fluorocarbon Elastomers are also called FPM or FKM o-rings. They are all the same! These are much more oxygen resistant and are typically recommended for inclusion in your save-a-dive kit as they are considered Nitrox compatible and better than the inexpensive nitrile o-rings. FKM o-rings have very good chemical resistance, oil resistance. 

Nitrile – This is a common hydrocarbon based synthetic rubber, with good durability and resistance to oils and acids. Also called Acrylonitrile-Butadiene Copolymers (NBR). It is important to note that nitrile is not very oxygen resistant – therefore if you dive a lot of nitrox with increased oxygen percentages you may want to look to have o-rings in your save-a-dive kit made from other materials.

Polyurethane – You don’t find a lot of these o-rings in scuba diving, they are milky white in appearance and typically only used in K-valves because they are extremely durable and can support very high pressures.

EPDM – Ethylene Propylene Diene Monomer are increasingly being used in scuba diving because it can be considered safer for breathing systems. It is not considered as durable as FKM o-rings and is not recommended to use with oil based products (so lubricants can lead to quick deterioration of these o-rings).

Did you know our ultimate save-a-dive kit has all the o-rings you need!

Does O-Ring Hardness Matter?

Depending on what the purpose of the o-ring is and where it is used within your scuba equipment different hardnesses are recommended.  O-ring hardness is defined by durometer. A durometer rating of 70 is considered soft while a rating of 90 is considered stiff or hard. You want softer o-rings in places where the two moving parts meet – like an SPG swivel or regulators. Harder o-rings are best for more static applications like use on a tank. A quick note about color. Many o-rings are black sometimes you will find FKM/FPM o-rings in brown which is helpful for distinguishing them from nitrile ones, and EPDM ones are sometimes purple. However the color of an o-ring is really not important and does not tell you a lot. You can easily have black FKM/FPM or EPDM o-rings.

O-Ring Sizes and Measurements:

You will typically see two different designations for o-ring sizes the S.A.E and the British BS-1806 standard. For most scuba uses you look at the last three numbers for the size. See the chart below for some details on the stands sized o-rings and their application.

OD –  is the outside diameter (the diameter from outside to outside)

ID – is the inside diameter (the diameter from the inside edge to inside edge)

CS – is the cross section of the o-ring (essentially the OD – ID)

Should you Lubricate Your O-Rings?

There is some debate in the industry of using silicone grease on o-rings where enriched oxygen is used. O-rings used in static situations don’t really need lubrication, dynamic o-rings should be lubricated but make sure you don’t use too much lube as the excess lubrication can accumulate and block ports within your regulator or SPG.

Whether you are new to the world of SCUBA diving or already a veteran, it cannot be overstated how important it is to make sure you have a save-a-dive kit as a key part of your scuba equipment.  If you are unfamiliar with a save-a-dive kit, it is a collection of tools, parts, items and safety equipment that can be used while at a dive site to repair your or another divers equipment when problems arise while out at the dive site. A well stocked save-a-dive kit allows you to continue the dive rather than having to call off the dive due to safety or equipment failure. 

Don’t Forget Your Pre-Dive inspection

It is always important to inspect your equipment before leaving home. Pre-dive inspections go a long way in preventing dive site surprises that require a save-a-dive kit. Deciding on what goes in your save a dive kit will depend strongly on what you can or are willing to repair at a dive site. It is important to think about your limits and your experience when it comes to deciding what items to add to your save a dive kit. There is no use adding in IP gauge to your save-a-dive If you have no idea how it is used or what to do with it. You don’t want extra junk logging a lot of miles travelling around in your dive bag for years!

Check out our ultimate save-a-dive kit to get you started on building your own customized kit!

A list of must have items for your save-a-dive kit.

So let’s look at what might be in a typical save-a-dive kit. You are in great shape if your kit has all of these items. Don’t think of this as a comprehensive list, as your situation or equipment may be different. Use it as a guide to direct you on where to start as you build your kit. Add or remove items from this list based upon your needs and the type of diving you do or equipment you have. This save-a-dive kit list is a great checklist to have the most typical situations covered.

Container – in my experience I found having a watertight container makes the most sense for any save-a-dive kit.

The perfect container keeps everything together and dry. This eliminates the need to dry out your save-a-dive kit after leaving the dive site. 

Tools – tools are critical in a save-a-dive kit, typically this will include: 

• Wrenches – common wrench sizes are ½’, 9/16’, ⅝”,11/16”, 13/16”, 15mm.
• Allen keys – various sizes but 4 & 5 mm are most common for High Pressure (HP) and Low Pressure (LP) ports on your 1st stage. 
• Pliers – extremely useful. Personally I have found a small set of needle nose sliders best to get into tight quarters on a lot of scuba equipment.  
• Screwdrivers – typically Phillips head and flat head screwdriver. These 2 types are usually all that are required. Always check your equipment to be sure you don’t need anything unusual like Torx or Robertson. 
• Scissors – a nice set of surgical shears are great for a number of uses. Uses include: keeping them in your BCD pocket for entanglements, cutting short pieces of cave line or completing repairs.
• O-Ring pick – useful for fishing out o-rings for swivels, tank connections and other places. Dental picks also work well for this.

Replacement parts – items that are quick and easy to change out at the dive site.

Without replacement parts you cannot dive safely and may need to end the dive due to equipment failure.

• Mask strap – quick and easy to replace. Any generic mask strap will get you back to diving in a few moments.
• Universal fin strap – fin straps tend to be a little more specific – check your equipment! In most cases you can get back in the water with a typical universal fin strap. 
• Mouthpiece – A torn or worn out mouthpiece to make your dive a struggle. A replacement mouthpiece and a zip-tie is super easy to replace and will get you back diving comfortably. 
• O-Rings – Are must have for any save a dive kit. Usually you can get away with a couple of the most typical sizes. A slightly larger range of o-rings will give you the ability to fix many different issues at the dive site quickly and efficiently. Personally I recommend that you spend a couple of extra bucks and make sure you have Nitrox-Compatible FMK / Viton O-Rings. These types of o-rings give you the flexibility to dive safely on Nitrox and are often little harder and more durable. Finally, pack a tube of food-grade silicone grease to lube up your o-rings before placing them on your equipment.
• Snorkel Keeper – super useful for a number of situations like keeping your snorkel attached. A snorkel keeper can also be used to keep an octopus connected to your BCD and easily accessible, or attaching cameras, flashlights or other accessories to your BCD D-Rings.

Accessories – other useful items that are a great add to a save a dive kit.

• Stainless steel bolt eye clips – great for connecting gear to your BCD. Because bolt eye clips are stainless they won’t rust and will be ready to go when you need them.
• Cave line – is nylon line useful again for typing up items or a whole host of situations.
• Elastic bands / chopped up inner tube – are also great for securing items to your BCD.
• Zip-ties – are truly one of the most useful items. They are not only useful for connecting a new mouthpiece to your second stage. Zip-ties can also be used to fix so many problems or issues that may  plague you at the dive-site.
• DIN-YOKE Converter – if you have a YOKE connector for your first stage it is often good to have one of these kicking around your kit if you travel internationally. Many places around the world use DIN connectors on their tanks. 
• Computer Battery – If you have a die computer it is a good idea to have an extra battery in your save-a-dive kit. Check your battery during your pre-dive inspection. It can be hard to quickly change a battery when at the dive site. 

If your kit has all of the items listed above, any even a few more you should be all set. The result of a well prepared save-a-dive kit is a more enjoyable dive. As a result of preparation many divers say they have saved a lot more dives than their own with a well thought out save-a-dive kit!