NAUI Trimix I
This class is designed to teach you to use helium and appropriate decompression gases to execute dives in the depth range up to 200ft.
Minimum Age 21.
250 logged dives, at least 10 must be staged decompression dives.
Advanced Nitrox and Decompression Certification. Prior Helium Certificati, Helitrox or equivalent is also required.
In general I will chat with each individual regarding their diving experience and motivation for the class. If possible I will try to schedule a review dive or obtain a recommendation from their previous instructor(s). In this class we certainly spend time working on basic technical skills however it is expected that these skills are in place for the class so that we can move on making dives.
The class has 6 lectures and 6 dives, This can be accomplished in a 5 day
class, or it can be broken down into weekend chunks over a period of
time. The class starts out with a skills dive and shallow
water session, this is then followed by progressively deeper
dives. The final two dives will be within a range up to 200 ft. The dives will be executed on our local wrecks ranging from
Pompano to the Keys. I usually include wrecks such as Hydro
Atlantic, Lowrance, Northern Light, Sucre.
It should be noted that participation in the class does not guarantee certification. Should you not get certified at the end of the class I will provide you with a guide as to which areas require more practice, and I will happy to assist you with working on this. In most cases it is not necessary to repeat the class, simply work on the skills that are outlined and then demonstrate you have mastered them. After the class you will be certified to plan and execute dives to a depth of 225ft, using appropriate Trimix mixtures and decompression gases including 100% Oxygen.
If you don't have any equipment already I strongly recommend you talk to me about what to buy before the class so that you don't wind up getting the wrong things:
Back Gas Tanks: The most popular tanks for this class are double steel tanks with a minimum capacity of 190cuft, for example double lp 95's. Double Aluminum 80's may also be used for the dives. If you need more gas than these hold, it is acceptable to stage more in an Al80 single tank, I will caveat this statement however with the caution that you will be staging three different tanks for some of the dives which will increase your task loading and require a higher level of physical fitness to manage these while swimming and while gearing up and exiting the boat. Dives executed using extremely negatively buoyant double steel tanks (for example PST) require the use of a drysuit, the goal is to ensure that the buoyancy of the entire system is not solely dependent on the gas in the diver's wing in the event of a failure.
Valves: Double tanks require a manifold. This should be
of the Din Valve type, and must have an isolator valve the design of which is
recommended to utilize barrel O rings. All should be DIN either 200 or 300
Decompression Tanks: The standard size used in class is AL40cuft tank. Two of these will be needed. The tanks must be rigged as you would a stage bottle, and should be O2 cleaned ready for use. The Deco tanks should be marked with MOD (which for the class will be 70) and the Oxygen Bottle should be marked OXYGEN and the MOD of 20. We will not be using steel decompression tanks/stages in the class.
Argon Bottle: For drysuit inflation in cold water an Argon
bottle is required when using Helium Mixes. The class is
taught in the Miami area, and the water is not cold, therefore I do not require
the use of an argon system. If one is used it must be rigged with a
regulator with an overpressure valve. The size of the argon bottle
can be either the 6cuft or 13cuft.
Primary and backup regulators: Both need to be high performance class A regulators. The primary regulator must be rigged with a 7ft hose and a lp inflator hose for the BC. The backup regulator must be rigged with an SPG, and drysuit inflator hose if diving dry, and a neckace bungie to hold it in place. DIN regulators are recommended.
Decompression Regulator(s): People frequently downgrade the regulator used for this purpose since it is not one that is used at depth, and the performance therefore is not as critical as those used for the back gas. Having said this, please don't go to extremes, using an old clunker can be both uncomfortable and dangerous in terms of CO2 buildup, so I recommend a good regulator for deco as well. This reg should be compatible or cleaned for use with nitrox mixes greater than 40%. It should be set up with a small SPG placed on a 6" hp hose, and the regulator hose length should be long enough so that it can be looped behind the divers head from left to right and breathed comfortably, without having an excessively long loop that is a potential snagging hazard. I use an Octopus hose for this, but I am a pretty short person if you are a big guy or tall I would try something like a 34-38 inch hose.
Buoyancy control device: The best equipment for this type of diving is a backplate with webbing harness, and a wing for buoyancy control and is required for the class. Not only is this the best configuration, it will be useful for EVERY kind of diving you might decide to take on in the future, including cave diving, trimix diving, or even catching lobsters on the reef. I have not dived with a regular BC for years. Wing size will vary depending on the tanks you are using (talk to me about what configuration you are considering so that we can work on wing sizes). Back inflation is mandatory for the class, a jacket style BC will not allow you to perform the required skills properly.
SPG for back gas and separate SPG for deco gases and stage gases.
Wrist Mounted Compass
Wrist Mounted Depth gauge and bottom timer plus backup depth gauge and bottom time.
(A computer can be used for this purpose, but will not be used in computer mode for the class)
I use a UWATEC depth gauge/bottom timer, and a second in my pocket for backup.
Backup Mask (one per dive team)
Two Lift bags, one needs to be 50# capacity.
Two spools or one spool and a reel. One must have at LEAST 250 ft of line
Note: Split fins will not work for this class.
Cutting Device, either small knife or shears.
One Primary Light and a backup light is required. Pistol Grip lights are not recommended.
Suit Pockets are recommended (these can be glued onto your wetsuit and will make your life alot easier)
Wetnotes. ( A slate can be used but the wetnotes are much more effective.)