Rec Tec Dive Calendar

When	Dive or Course
4th Jun 13 to 9th Jun 13	Lermontov Week/ PADI Deep, Wreck & TDI Advanced Wreck Courses Port Gore
29th Jun 13	Riwaka Cave Trip Riwaka
20th Jul 13 to 26th Jul 13	Fiordland 2013 Fiordland
17th Aug 13 to 25th Aug 13	Deep Cavern Course Mount Gambier
7th Sep 13 to 8th Sep 13	Hippolas Wreck Picton

A brief overview of Go Dive’s most popular courses, including certification and logged dive pre-requisites and equipment requirements.

PADI NITROX

Nitrox is about bottom time not depth. It allows you to extend your bottom time and maximise your investment in all your kit and training. With planning consideration it can also add a conservative eliminate to your diving in some situations.

Your understanding of decompression theory and the importance of proper dive planning will be expanded; you will complete at least two Nitrox dives with Go Dive on the Lermontov.

Pre-requisite
Open water diver

Kit requirements
Standard recreational diving kit (rental available)

Go Dive supplies
Nitrox compatible cylinders
O2 Analyser
Gas Blending services

TDI ADVANCED NITROX

Advanced Nitrox talks about mixes above the standard 22 to 40%. It will give you the ability to use high levels of O2 breathing mixes to greatly increase no-decompression bottom limits at moderate depths and to use high level breathing mixes to speed up decompression times, as well as to enhance you’re off gassing during a safety stop.

Pre-requisites
Nitrox certification
25 logged dives


Kit requirements
Standard dive kit
SMB and finger spool
U/W Slate

Go Dive Supplies
Nitrox compatible cylinder
Sling/Stage cylinder and regulator
O2 Analyser
Gas Blending services

TDI DECOMPRESSION PROCEDURES

Every dive you do is a decompression dive, it is just that some require a mandatory stop and some just a safety stop. This course helps you understand the principles behind the dives you plan that require a decompression stop. How to use the equipment that may be used to execute these dives and will introduce you to diving using twin cylinders. The course is in most cases run in conjunction with the Advanced Nitrox. Although a Nitrox certification is not a pre-requisite, it is highly recommend as it allows you to accelerate your decompression using high percentage mixes of Nitrox or 100% O2.

Pre-requisites
Open Water Diver (Adv Nitrox highly recommended)
25 logged dives

Kit Requirements
Standard dive kit
SMB & Spool
Underwater Slate or wet notes
Backup Mask
Wing & Harness (can be rented from Go Dive)
2nd Regulator (can be rented from Go Dive)

Go Dive Supplies
Single and Twin, O2 compatible cylinders
Deco cylinders
O2 Analyser
Gas Blending services

PADI Advanced Wreck

Warning wreck diving can be contagious, especially when diving a wreck like the Mikhail Lermontov. It can also be hazardous to the unprepared and correct wreck diving techniques and equipment are essential to stay safe. Recreational wreck courses only allow you to stay within the recreational zone of a wreck, however often the best visibility and points of interest are deep within the wreck, take for example the engine room of the Lermontov.

The Advanced wreck course will cover such skills as proper line deployment, lost line and loss-of-sight techniques. We will cover reverse finning, helicopter turns, plus much, much more. As an instructor, I would say this is one of the most fun and rewarding courses by far.

Pre-requisites
Deco Procedures or equivalent (Adv Nitrox highly also recommended)

Kit requirements
Standard dive kit or wing and harness (can be rented from Go Dive)
Wreck reel and finger spool
Back up mask
Primary light
Backup light
Underwater slate or wet notes

Go Dive will supply
Sling cylinder
Twin cylinders if required
Practise wreck reel
Gas blending services if Nitrox qualified


These courses are listed in an order of progression that is recommended by Go Dive and their instructors. Although it isn’t necessary to follow this flow of learning, the learning of new skills and knowledge development fits well, with skills and knowledge following naturally onto the next level. As an example to complete the advanced wreck training without Adv Nitrox training would severely limit your time on some wrecks, including the Lermontov. Example being a dive on air into the engine room at 33m with a BT of 40 minutes would result in a 9m stop for 2 minutes, 6m stop for 8 minutes and a 3m stop for 23 minutes or 73 minutes total RT. Where the same dive on Nitrox 32% using 100% deco gas at the 6m and 3m stops would result in a 12m stop for 1 minute a 9 m stop for 2 minutes, 6m for 2 and 3 for 5 minutes, so a total of 52 minutes RT with ascent times taken into consideration, so 21 minutes less in the water and 21minutes less gas required.

* Calculations based on Bulhmann air tables and Deco Planner software

Welcome to Go Dive’s Rec Tec diving page

The term technical diving was coined in the early 90’s and is misinterpreted by many as a type of diving set-a-side for adrenalin junkies and those with unlimited disposal income.

Since the early 90’s technical diving training, techniques and equipment have evolved faster than any other area of the dive industry, to the point where the line between recreational and technical diving is no longer definable. Go Dive prefers to use the term Rec Tec as a more appropriate term in today’s market

Go Dive is lucky to have one of the best wreck dives in the world on our back door step, a wreck which can be made as challenging as your training, kit and experience allow.


We are now hosting on a very regular bases rebreather and open circuit divers and have become the preferred training location for many Instructors whom teach Rebreather and Advanced Wreck training. In fact we are now probably one of New Zealand’s most active Rec Tec facilities.

Go Dive run regular TDI & PADI Nitrox, Adv Nitrox, Decompression Procedures Gas Blender and Advanced Wreck courses, based from our fully equipped dive lodge in Port Gore.

Here is why you might consider Rec Tec and how it will increase your comfort and skill level to a point where you will maximise your enjoyment underwater.

Recreational courses offered by the major training agencies focus on the basic skills of diving, enough to where you can comfortably dive independently of a dive professional in a particular environment. None of these courses allow enough time for you to truly master your buoyancy to a point where you can with ease, hover horizontally in the water collum while performing tasks such as deploying an SMB or removing and replacing your mask. Nor do these courses take you to a point where you can communicate with your buddy beyond the most basic level or calculate your air consumption rate, a great skill if you want to know how long your gas is going to last underwater, a pretty important part of dive planning.

Buoyancy control, gas management and correct finning when wreck, cave, or decompression diving is critical, without these skills things can go belly up pretty quickly. Right from the Advanced Nitrox course we will be discussing and developing your weight system distribution and buoyancy techniques, as well as discussing and practicing some useful hand signals, which can be used to determine time, pressures and depths with your dive team during the dive.

A BRIEF EXPLANATION OF THE KIT ASSOCIATED WITH REC TEC DIVING

DIN Valves

There are two types of valve fittings for SCUBA cylinders. Open face A-Clamp which until recently have been a standard in New Zealand and 200 Bar or 300 Bar DIN.

Rec Tec divers prefer the DIN fitting as the o-ring is in-captured in the valve and far less likely to fail than the A-clamp o-ring that can extrude itself from its seat, if the regulator is given a good thump while moving through an overhead environment.

Sling Cylinder and Regulator

Diving at depth and in an overhead environment like a wreck requires certain redundancy, with air supply being the one that needs to be given the most consideration.

Many divers begin their journey into this environment by simply adding a single 6 litre alloy cylinder and regulator to their standard recreational kit. This not only gives you air redundancy in case of loss of back gas, but the ability to accelerate your decompression by carrying a decompression gas which is at a higher O2 percentage than your back gas.

The investment in such kit is under NZ$1000.00, but the rewards in way of expanding your diving experiences are huge.

Twin Cylinders and Regulators

Like the sling tank just mentioned, the reason for twins is again about redundancy. The difference is that in most cases they are carried on your back, are of 12 Litre capacity or greater and linked together by an isolating manifold. This configuration gives you a far greater volume of gas, with each cylinder being able to be isolated from the other in case of a hose or o-ring failure on one regulator or valve. This allows you to plan and execute dives for a longer period of time than a just a single and a sling would allow.

With the right planning when purchasing kit for the first time or replacing existing kit, all you need to do is add a second cylinder, manifold, bands, regulator and wing and you’re good to go.

Semi Closed and Closed Circuit Rebreathers

On inhalation we breathe in 21% oxygen and on exhalation we exhale 16% which works out about 25% of the O2 inhaled. Our tissues metabolize this O2 to live and work, and in turn produce carbon dioxide (about 3-4%)

A rebreather can be presented as a fairly simple concept. Take this carbon dioxide out of the exhaled air and add some O2. A rebreather is essentially a breathing loop; this consists of our lungs, the mouth piece, the counter lungs, a scrubber and the hoses that connect the components. The exhaled air goes into the exhalation counter lung, O2 is added before it goes to the scrubber, this gas then heads to the scrubber, where CO2 is removed through a chemical reaction, then heads into the inhalation counter lung, and then back to the divers lungs.

There are four main types of rebreathers available to divers. The O2 closed circuit, the semi-closed circuit (SCR), closed circuit electronic (CCR) and manual closed circuit (CCR)

The main advantage of SCR and CCR's is that they conserve gas, and in the case of trimix diving this allows for a huge saving in helium. For example an Open circuit dive using trimix 18/40 to a depth of 70m for 90 minutes total run time would cost you in New Zealand around $250.00, on a SCR using a 5/1 mouthpiece it would be around $75.00 and on a CCR around $50.00.

In the case of the CCR they mix your gas on the fly, so you get the optimum blend of gas for the depth, this can reduce your decompression obligation.

SCR rebreathers in many cases marry up with your existing scuba kit and tap into the gas you have blended, they are simpler to use and far cheaper to buy. If your intention is to do shallow moderate depth dives, then these are a great option.