During my recent business trip to Dahab, I was able to squeeze some free time and finally had a chance to try the Hollis Explorer Rebreather. http://vimeo.com/79204979
I have been diving with CCR and SCR before and I was really curious to breathe through ‘the hybrid system’ (as Hollis calls the Explorer) which is a mix of the two – that is, neither fully closed nor purely semi-closed.
Basically the unit uses a single – nitrox – gas that is electronically controlled to achieve an optimal balance between oxygen partial pressure (pp02) and dive time.
My diving experience with the Explorer Rebreather was made possible thanks to my friend Aron @ Team Blue Immersion/Dahab Divers.
After Aron’s customized presentation on the features of this specific unit and its benefits (as mentioned earlier I have experience in Rebreather diving), it was finally time to play with the ‘toys’.
Assembling the unit is really straightforward: you can see that Hollis has put some effort into making the Explorer ‘novice friendly’. By following a logical order you can easily connect the different parts (after proper lubrication).
The next step was a computer-assisted pre-dive check: just follow the computer instructions to perform specific tests to verify the correct assembling and proper functionality of the unit.
The unit can be used with or without a CO2 sensor; in the event that the sensor is unavailable (as in my case) you have to complete the famous ‘5 minute pre-dive breathing’ stage (fully supported by the computer).
Once successfully completed you get a green light and a ready to dive message!
Donning the unit is quite easy, it feels light …and I was lucky enough that the previous user had a body shape similar to mine, meaning the harness was a perfect fit!
Finally in the water: first, a quick equipment check on the surface, then a bubble check underwater and the required flick through the different computer readings ….and then finally… silence! After spending a few minutes to become familiar with the kit, and practice some safety drills, we go for our 70-minute dive around the Lighthouse area.
Within just a couple of fin kicks we’re greeted by a nice Napoleon wrasse – and that’s typical with Rebreathers; the reduction in noise allows unique wildlife encounters. Not only that, but the silence combined with the warm, moist air you breathe makes you really feel comfortable and you really don’t want to leave the water…
In terms of safety, the Explorer has a “Bail-out” mouthpiece which enables a quick one-handed switch from closed-circuit to open circuit supplied by on-board gas. If the Explorer detects a problem, the diver is alerted in two ways: firstly via the “heads up” LED display which provides the unit status throughout the dive (signalling green for normal operation, or red to bailout) and secondly, the regulator in your mouth vibrates. The unit also has a ‘Loop Control Valve’ that assists in managing loop volume during ascents.
My experience with the Hollis Explorer was great – I enjoyed every single second of my dive. I can say that the Explorer combines the safety of semi-closed Rebreathers with the efficiency, simplicity of use and ease of breathing of technical closed circuit Rebreathers. It’s compact, lightweight and extremely easy to use!
Despite the fact that it had been a few years since my last CCR/SCR dive, I was able to manage my buoyancy and get the best out of the Explorer unit relatively quickly. It usually takes few dives before you get the hang out of it, and that’s the reason why I would highly recommend a recreational Rebreather course to help you get accustomed to this style of diving.