Thursday November 27 , 2014

Explorer Loop Control Valve (LCV)

Rebreather divers must learn to maintain the loop volume close to its optimal level for their particular model of rebreather. The Hollis Explorer’s unique ‘Loop Control Valve’ (LCV) takes the pain out of managing loop volume during ascents. No more dumping gas through your nose – that’s one less thing to worry about!

The Explorer vents excess gas gradually in tiny bubbles at the top of each breath by means of a unique hydrostatically-balanced Loop Control Valve (LCV), that maintains a constant loop volume, it releases gas from counterlungs at approximately the same pressure and rate. As such the Explorer feels like a closed circuit rebreather. The loop controller also makes buoyancy control easier.

LCV makes buoyancy control easier.

The loop controller also makes buoyancy control easier.

The breathing ‘feel’ of EXPLORER is partially controlled by the LCV. Having removed the case cover this can be seen underneath the Canister. This is an adjustable valve (over a small range). Moving the valve to the left vents more easily and to the right it vents at a slightly elevated pressure.

eXplorer LCV

Adjust the LCV

Typically a small frame diver will start with the LCV all the way to the Divers Left and all others at the mid way point.  Since all programs are to have a confined water session, during that session the instructor should work with the student to properly adjust the LCV for the proper feel and to keep the unit at a min loop volume for the best breathing and the least amount of weight.


As a guideline if you have Puffy cheeks or BOV being pushed out of the mouth  then move LCV to the left.  Also, if the ADV consistently kicks in during normal inhalation – move LCV to right; Hard to exhale and need to blow out gas from around the mouth piece- move LCV to the left or if the mouth piece being forced into the mouth then adjust the LCV to the right.


Diving with Dolphins in Sydney

Mother nature often gives scuba divers some amazing experiences in the waters around Sydney. Over the past month on a number of the divers on our guided shore dives and  the students on a number of our dive courses have experienced dolphins diving with them. The dolphins have been encountered on a number of days both at Oak Park and The Steps.

Enjoy diving together

Bottlenose dolphins are well known as the intelligent and charismatic stars of many aquarium shows. Their curved mouths give the appearance of a friendly, permanent smile, and they can be trained to perform complex tricks.

These dolphins are sleek swimmers can reach speeds of over  30 kilometers an hour so as divers they either come to the divers or the divers don’t get to see them. In the case of the Oak Park sightings the dolphins came to the divers over 3 consecutive days.

Bottlenose dolphins normally travel in social pods and communicate with each other by a complex system of squeaks and whistles.  As divers we often see pods of dolphins as we are entering or exiting the water at sites such as Oak Park or Captain Cooks Park at Kurnell.

Bottlenose dolphins track their prey through the expert use of echolocation. They can make up to 1,000 clicking noises per second. These sounds travel underwater until they encounter objects, then bounce back to their dolphin senders, revealing the location, size, and shape of their target.

When dolphins are feeding, that target is often a bottom-dwelling fish, though they also eat shrimp and squid. These clever animals are also sometimes spotted following fishing boats in hopes of dining on leftovers.

For divers who have witnessed wild dolphins, there is often no comparison to any other ocean experience. For those who have yet to experience it, it certainly is an encounter to look forward to. So plan to go for a dive soon.

Dolphin Joining a Advanced Open Water Course at Oak Park



Why Learn Technical Diving??

Many people hear the term Technical Diving, and immediately think of heavy, cumbersome equipment and additional risk whilst scuba diving. This perception needs to change….

Traditionally, technical scuba diving has meant going beyond recreational scuba diving limits, and included one or more of the following:

  • Diving deeper than 40 metres
  • Required stage decompression
  • Diving in an overhead environment beyond 40 linear metres of the surface
  • Accelerated decompression and/or the use of variable gas mixtures during the dive
  • Use of extensive equipment and technologies

Yes, it is true, many people learn Technical Diving to challenge themselves, and explore places that no one else has ever seen. There is obviously excitement and adventure that goes with this!

But for many, learning Technical Diving means they are better prepared as a diver, should something on their recreational dive not go as planned.

I have seen divers accidentally go into decompression (past the No Decompression Limit on their computer) on 20 – 30m dives where they have been distracted by their surroundings. I have also seen divers go into decompression on dives where something happened underwater that caused these divers to stay longer at depth than they were supposed to. I have almost done this myself in only 20m of water!

On both of these occasions, the divers were not aware of what to do when this happened. They had only ever thought of technical divers as those people who dived extremely deep with lots of cumbersome equipment. If they had learnt the basics of technical diving, they would have been prepared to handle these situations when they occurred.

Many Technical Diving courses don’t allow you to learn just  the basics of technical diving, they require you to sign up to push yourself deep and with lots of equipment. And then we have the PADI TecRec program…..

Technical Diving

The PADI TecRec Difference

PADI TecRec courses are the quality benchmarks in the tec diving world due to their rigorous, yet logical, training sequence and the PADI educational materials that support them. TecRec courses are instructionally valid and have a seamless course flow that takes you from a new tec diver to one qualified to dive to the outer reaches of sport diving if you wish to. Each level introduces you to new gear and procedures to extend your dive limits, but does not require you to take the next level if you do not wish to.

The first PADI TecRec level (Tec 40) does not take you any deeper than recreational dive limits and does not require you to wear cumbersome equipment. It does however, teach you how to manage limited decompression for planned decompression schedules. So although you may not think yourself a Technical diver, and would not push yourself to the limits of where many Technical divers go, this additional training and the Tec 40 level is invaluable to any recreational diver, and will hold you in good stead should dives not go quite to plan.


Vanuatua Christmas Dive Trip

The Hideaway Island Resort and Marine Sanctuary is situated in Mele Bay, a 20 minute ferry ride from Port Vila, the capital of Vanuatu. Surrounded by clear turquoise waters and coral reefs, it is one of the few places where you can hand feed hundreds of "tame" brilliantly coloured fish in a safe protected area. This is an experience you wont forget!


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