DIVER TESTS: Oceanic Zeo

Oceanic ir viens no lielākajiem dive-gear manufacturers. Back in the 1970s, its first regulators was the Omega, a bold servo-assisted, side-exhaust model renowned for being an easy breathe. Servo-assisted mechanisms are associated with high performance, but are expensive to build and can require more maintenance than conventional second stages.

Skaits regulators manufacturers have experimented with servo second stages, but few have persisted.

Oceanic made it to an Omega 111, but the current second-stage line-up returns to traditional diaphragm-operated levers and underslung exhaust valves.

In the top-of-the-line Zeo, many interesting features are concealed within the conventional-looking first and second stages. So how well does it stands up to Oceanic’s claims of easy breathing under demanding test conditions?

Pirmais posms

The Zeo uses the Oceanic FDXi first stage. Made from brass with a PVD coating to further resist corrosion, it’s a compact, lightweight diaphragm design, the type increasingly seen on high-performance regulatori.

If a first stage can’t feed a regulators pietiekami daudz gaisa, tiks pasliktināts pat labākais otrā posma sniegums. Dziļumā, īpaši zem 30 m, gaiss zem spiediena kļūst daudz blīvāks un jūtas viskozs, kad to ieelpojat, savukārt virkne fizioloģisku izmaiņu arī apgrūtina elpošanu.

To help mitigate such challenges, the FDXi is actually overbalanced. It doesn’t increase the pressure of the air it sends to the second stage to exactly match that of the surrounding water – 4 bar at 30m, for example – as a normal balanced first stage would do. Instead, it delivers air at a slightly higher pressure than that of the surrounding water.

Oceanic also claims that its internal air routeing reduces the pressure drop that occurs when air goes around a corner. This happens with most first stages with hoses that run off the side of the casing. This drop reduces ease of breathing under high demand, so maintaining pressure is important.

Mulsinoši, ka Zeo, kā to prasa ES tiesību akti, ir apzīmogots ar EN250 novērtējumu, lai to varētu lietot viens nirējs līdz 50 m, taču šķiet, ka tam nav EN250A sertifikāta.

Biju pārsteigts, ka tāds a regulators would not meet the higher A standard. EN250A confirms that a regulator has passed machine breathing tests at 30m when the primary and an astoņkājis vienlaikus tiek smagi elpotas.

This provides a degree of confidence in a regulator’s ability to be used for emergency sharing. It’s an EU requirement that the EN certification is stamped on the regulator.

Lai apstiprinātu, ka Zeo atbilst EN250A kategorijai, bija nepieciešams daudz pētījumu. Tas nav atzīmēts vietnē, iespējams, atspoguļojot Ziemeļamerikas aizspriedumus.

The importer stated that all Oceanic regulatori do meet this standard, and I finally found the written confirmation buried in a generic manual for Oceanic regs.

FDXi ir paredzēts lietošanai ūdenī līdz 4°C. Vēsākiem apstākļiem ir pieejams papildu aukstā ūdens komplekts, kas izmanto gaisu, lai izolētu ārējo diafragmas atsperi no ūdens.

This also protects the spring and diaphragm from contaminants such as silt that might inhibit performance. The FDXi can be used with up to 40% nitrox without any mods.

There is a high-pressure port for pressure gauges and transmitters on either side of the first stage. There are also two mp ports, one of which is used for your primary second stage, on the left and right sides. As with most diaphragm first stages, these are fixed, not swivel-mounted.

You can choose from yoke, 200 or 300 bar DIN connections. I prefer 300 bar DIN and carry a simple screw-on yoke adapter in case I can’t hire a DIN cylinder. Oceanic offers a yoke adapter as an option.

Otrais posms

The Zeo, as befitting a high-end second stage, is pneumatically balanced. A second stage supplies air only when you want it by using a spring to keep a valve closed until you inhale.

The problem with an unbalanced second stage is that as you descend and water pressure increases, so does the pressure of gas leaving the first stage. It tries to push the second-stage valve open, so the spring must be strong enough to hold it closed, even on deep dives, until you inhale.

Lai pārvarētu atsperes pretestību, jāizmanto plaušu spēks – pamatā sūkšana. Viss, kas palielina elpošanas pretestību, nav noderīgs un kļūst problemātiskāks, jo lielāks ir jūsu pieprasījums pēc gaisa.

Vismaz jūs izmantosit vairāk gaisa, jo enerģija tiek iztērēta tikai ieelpošanai.

A pneumatically balanced second stage uses a weaker spring than an unbalanced model. It harnesses air pressure by allowing air to surround the spring. This is used to supplement the spring’s strength as needed. On deeper dives, air pressure increases to balance the air pressure coming from the first stage.

A lighter spring can be used, just strong enough to hold back the incoming air at low surface pressure, so the second-stage valve should be easy to open with the least amount of effort on your part, regardless of depth.

The lung effort you expend to open the valve and get the air to flow is called cracking effort. The Zeo has user-adjustable cracking effort. It can be dialled in at any point during a dive by turning a large scalloped knob.

Once you have cracked the valve and the air has started to flow, the venturi takes over most of the inhalation effort for you.

Lielākā daļa no regulatori I’ve owned have adjustments, but I’m not a fan of using them. Increasing cracking effort might be something you need to do if strung out on a reef hook or shotline and facing into a roaring current, but I’ve never experienced a freeflow in those circumstances myself.

Smagi peldot pret spēcīgu strāvu, es vēlos vieglāk elpojošu, visefektīvāko regulējumu un labāku plaušu komplektu.

Vienkārša svira ļauj izslēgt Venturi cauruli, lai novērstu brīvu plūsmu, kad Zeo neatrodas mutē. Venturi slēdži ir zināmi arī kā niršanas/pirmsniršanas vadības ierīces.

Under water, they should never be in pre-dive mode. A flexi hose links the first to the second stage, where it attaches via a ball joint.

in Use

The Zeo second stage is very light and there’s no noticeable weight on your jaw, even on dives exceeding an hour.

The mouthpiece bite-tabs are very soft which, I suspect, also adds to the feeling of comfort. The flexi-hose is unnoticeable when you turn your head.

Neatkarīgi no tā, vai lodveida locītava patiešām palīdz, es nebiju pārliecināts. Es nejutu, kā tas kustas, kad novietoju uz tā roku un skatījos pa kreisi un pa labi un uz augšu un uz leju. Mazais dizains ļauj pietuvināt aci skatu meklētājam, un izplūdes caurule T lieliski novērš burbuļus no jūsu redzes lauka, un tas ir noderīgi zemūdens fotogrāfiem.

Nejauši ievietojiet šo regulu otrādi, un ir maz ticams, ka tas jūs izkustinās maska. To notīrīt apgrieztu, iztīrot vai izelpojot, ir viegli.

I’m no fan of breathing-adjustment controls, but most high-end regs have them. It’s easier to compete by fitting them, even if they go unused.

Plaisāšanas piepūles vadības ierīci ir viegli satvert.

Jauka funkcija neļauj to pārmērīgi pievilkt. Venturi sviru ir viegli atvērt vai aizvērt. Atstājiet Zeo plaši atvērtu, un tas ir labi veikts ar ļoti gludu elpošanu.

Astoņkāju tests

My deepwater, high-demand reg-sharing exercise aims to simulate a situation in which two divers are breathing hard from a single first stage using both a primary and secondary or astoņkājis Vienlaicīgi.

Nē astoņkājis was supplied, so I fitted another manufacturer’s top-of-the-line pneumatically balanced second stage, adjusted for the easiest breathing possible. With experienced instruktors Nick Balban, I descended to 32m.

Lai paātrinātu elpošanu, mēs, cik vien spēcīgi varējām, spurām pret enkuru. Kad es jutu, ka esmu sasniedzis savu maksimālo elpošanas ciklu, Niks ieradās astoņkājis, un, palielinoties viņa darba ātrumam, es mēģināju atklāt jebkādu Zeo izraisītu elpošanas pretestības palielināšanos. ES nevarēju.

Tas, ko mēs nevaram subjektīvi novērtēt, ir elpošanas darbs — tas tiek mērīts elpošanas simulatorā kā daļa no EN sertifikācijas procesa. Bet es uzskatu, ka mūsu reālās pasaules pārbaudījums ir pārliecinošs un pūļu vērts.