March 2000 Show me the way to go home

Show me the way to go home - Scubapro Uwatec Neverlost Octopus that says you care - Aqua-Lung Low Profile Octopus Why an Inspiration needs a Nexus - Buddy Nexus Behind you! -I sea U mirror

John Bantin has been a full-time professional diving writer and underwater photographer since 1990. He makes around 300 dives each year testing diving equipment.

Finding your way back from whence you came can be quite an important aspect of a dive. The Uwatec Neverlost, which has just been voted Innovation of the Year by Diver readers clearly impressed by the concept, promises to make this easy. It comprises a beacon or "boat unit" and a "diver unit", and works by ultrasound.
Such a system could be of particular help to wreck divers who prefer to get back to their shotlines before making an ascent, or night divers who would like to be sure of locating their point of entry, whether it be a moored boat or shore access.
The beacon emits a signal on one of four pre-chosen frequencies and the diver unit registers the strength, giving both direction and distance. You can scan for other units which might be in use on a site before choosing which frequency to use.
An LCD on the diver unit indicates whether it is being pointed at the beacon and the number of bars on the display gives a progressive indication of signal strength. Pressing the control button on the unit translates this into an approximate distance. There are two range settings, switchable during the dive.
The Neverlost diver unit is said to be able to pick up the ultra-sonic signal of the beacon from as far as 300m, so it should suit most wreck dives. I tried it successfully over more than 150m. However, it works by line of sight, so make sure to attach the beacon so that it cannot be obscured by solid objects.
Part of the art of using ultrasonics is knowing where to deploy the beacon. I found that it worked best on a line between 5 and 7m from the surface. That way its signal did not reflect intermittently from the broken underside of the surface, yet the unit was high enough to "see" me above the topography of the sea bottom. Don't expect simply to chuck it in and then find it later!
Up to 30 receivers will work from one beacon, and the UK distributors hope that dive clubs will buy one so that each member can then buy a locator. Otherwise its obvious market is the liveaboard or day dive boat. The manufacturer would clearly like to see boat-based dive operators worldwide buying beacons and supplying dive units to their customers. That, however, would represent quite a substantial investment.
Both units are big, solid pieces of equipment, each around the size of a good diver's light. Don't confuse them with those cheap sonic devices available from the Far East. My companions on a Red Sea night dive last year will remember me climbing back into the boat suffering from severe sense-of-humour failure when I lost such a cheap beacon. Luckily it had a little tell-tale red light that enabled the crew to spot it from the RIB in the dark later, so I was able to dive back down and get it. In the event the distributor of that one decided not to import it.
After using the Neverlost for a while you get to be able to distinguish between direct readings from the beacon and those that have been reflected from other surfaces such as nearby coral reefs or rocks. I reckon it would be less help if one was in a hurry (low on air, for example) but if you took your time it would probably get you safely home.
One diver decided to stick with me because he knew I was unlikely to get lost. However, when he stopped to take a photograph I disappeared from his view, and he had to resurface several times before getting safely back to the swim platform. I had no such problems!
Provided that you find yourself in the right circumstances, with no other surfaces off which the ultrasonics can reflect, the Neverlost works well. But be on the safe side and use a compass too.
A pair of Neverlost boat and diver units costs £595 and additional diver units cost £300 each.

Scubapro (UK) 01256 812636

PLUS	MINUS
+ A worthwhile contribution to diver safety + A good toy for the gizmo collector	- Not totally reliable for navigation in circumstances that allow for confused sound reflections - It is anothersubstantial item to carry around - Quite expensive. Isn't there danger of the beacon being stolen from the downline?

Octopus that says you care
It was not so long ago that the British Sub-Aqua Club declined to recommend octopus rigs, on the basis of the extra cost incurred. Instead, it taught everyone to buddy-breathe using a shared regulator.
It was a good party trick and built in-water confidence during pool training sessions, but it did little to save life in dire emergencies.
Meanwhile the rest of the world was fitting alternative second stages to its regulators in order to reduce life-risking incidents.
Gradually sanity prevailed and British divers started doing the same. But they usually fitted a second stage from an old unwanted regulator as a makeshift octopus.
I have in the past been offered an octopus that hardly worked, just at the moment I ran out of air. It wasn't funny. Surely the emergency rig should if anything be a better performer than the one routinely used?
In these more enlightened times, we see high-performance octopus rigs with long hoses, and even rigged on the opposite side to the diver's main second stage. This makes it much more convenient for another diver, presumably not in the most co-ordinated state, to obtain emergency air.
The Aqua-lung Low Profile Octopus goes a stage better. It has been designed from the outset for the job for which it is intended. It is on the end of a 1m-long bright yellow hose, has an efficient break-away retaining clip, can be used either way up and has an easily accessed purge control. All the troubled diver has to do is take it and stick it in his mouth.
Now I would be the first to agree that we live in an uncharitable society. When I bought a friend an octopus rig as a Christmas present, I was quick to point out that it was not for his benefit, but for mine!
Divers seen kitted up with Octopus rigs like Aqua-lung's are making a statement. They are thinking of their buddy.
The Aqua-Lung Low Profile Octopus costs £90.

Aqua-Lung UK 0116 212 4200

PLUS	MINUS
+ Designed for its purpose + Says that the wearer thinks of others	- Little direct benefit to the buyer, who hopes never to need it

Why an Inspiration needs a Nexus
Believe it or not, it has been known for certain diving equipment suppliers to intimate that they have a new product on the market, send me an example, let me test it and only then reveal that they don't plan to release it should it get bad reviews! I have to point out that Diver is here to test products on behalf of its readers, not to provide a market research service.
That said, so long as I know it's a prototype I'm testing, and depending on the product, it can be something of a privilege to gain access to an item before anyone else.
Because foreign-made items are available in the UK only once the distributors receive their stocks, opportunities for a journalist to try something ahead of the rest of the diving public are normally non-existent.
However, AP Valves is UK-based and Martin Parker, its MD, allowed me to try the Buddy Inspiration rebreather when it was still in prototype form.I became an enthusiastic supporter of the closed-circuit concept, and was not disappointed when the production model appeared.
A closed-circuit gas-mixing rebreather offers the advantage of a decompression obligation far lower than that available from ordinary open-circuit scuba or semi-closed circuit rebreathers.
However, apart from executing a pre-planned dive using Proplanner or Abyss software on a PC, there has until now been no accurate way of taking full advantage of this. I have been using an expensive three-mix computer (the Nitec 3), dividing my dive into three phases (eg 21 per cent O2 at 50m and less, 32 per cent O2 at 30m and less and 52 per cent O2 at 15m and less) and switching accordingly as I ascend.
What every Inspiration user has cried out for is a dive computer dedicated to the CCR and the constant partial pressure of O2 it allows you to breathe. The Buddy Nexus is exactly that.
I take some credit for suggesting to Martin that he approach Esa Raivo at Benemec in Finland with a view to producing such an item. At first glance the prototype he gave me looks much like other Benemec computers, sold under various brand names including Orca, Zeagle, Ocean Reef and Dacor.
You can choose two set points for the ppO2 when using an Inspiration, so the same is the case with the Nexus. You can also predetermine the depth at which you will change from the lower to the higher set-point on the way down and the depth at which you will change back on the way up.
This can be set to adjust automatically (by the depth-sensor) or you can try to change it yourself during the dive. This does involve some dexterity with a "tap-switch", so I preferred to keep it simple and left the switch-over in "auto" mode.
You can select one of two degrees of conservatism in the computer's dive table and one of four levels of altitude, as well as salt or fresh water. After a dive any of the settings can be altered or the Nexus can be changed back to open-circuit mode.
In CC mode it remembers set-points and switching depths unless you change the battery. In ordinary open-circuit mode it needs to be reset for any particular nitrox mix before each dive, as it defaults to air.
I'm cautious to the point of being a super-wimp. Although I used the Nexus at "sea-level", and in its least conservative mode, I chose to pre-set a ppO2 of 0.6 and 1.2 bar when in fact I was using 0.7 and 1.3 with the Inspiration. I also used it with the freshwater setting, which meant that it showed depths slightly greater than actual.
I pre-set it to switch to the high set-point at 12m on the way down and back to the low set-point at 7m on the way up. If this sounds like gobbledegook, I know that any Inspiration user will know what I mean!
Everything pre-set, I strapped the Nexus to my arm and went diving with it. Martin had said that he didn't expect me to use the computer to its full potential. Certainly the figures for decompression it throws up are so far removed from those normally seen by an open-circuit scuba diver that it requires a giant leap of faith. A dive to 30m for one hour can see you back at the surface in less than 1 hour 15 minutes. That's the magic of constant ppO2, but it takes some getting used to.
I got it down to within three minutes of going into deco-stop mode, but as I was diving at Cocos, where it is rarely advantageous or possible to go deeper than 40m, this in itself was something of an achievement.
However, the no-stop time poured back on as soon as I ascended a few metres and at depths of less than 18m the Nexus always seemed to show 199 minutes of no-stop time remaining.
During the no-stop part of the dive, CC (indicating that the computer is in closed-circuit mode) is displayed, but once you get into deco-stops that part of the display shows the ceiling depth instead. The Nexus doubles as a two-mix (per dive) ordinary open-circuit nitrox computer when you need it.
AP Valves supplies a comprehensive manual almost as massive as that supplied with the Inspiration.
My criticism must be my usual one with all Benemec products, which is that the peripheral information displayed is too small for my poor old eyes to read easily. As this was a prototype I'm sure the production models will have an easier-to-read display.
There is nothing else like it available, so I imagine that every Inspiration user will have to get one.
The Buddy Nexus costs £350, but no doubt it will be offered more cheaply as part of the Inspiration package.

AP Valves 01326 561040

PLUS	MINUS
+ Specifically designed for use with Inspiration rebreathers + Can be used for open-circuit air/ nitrox scuba + Good price for what it does	- Complex wet-finger sequences to set it up

Behind you!
The silliest diving accesssory ever to come to my attention is the I Sea U rear-view mirror for divers. Ideal for anyone who wants to cause a stir at the dive site, it is made from Christmas-cracker-quality plastic and clamps to the top of the mask, with the mirror mounted on an extended arm ahead. It reminds me of a Jerry Lewis movie called The Nerd.
It is said to be perfect for those divers who are paranoid about man-eating sharks (I can guarantee that you will never see one coming if you wear this product), those who worry about their mates turning their air off during a dive, and that minority of divers who ride to the dive site on a bicycle while fully kitted.
I had difficulty finding anyone willing to be photographed wearing the I Sea U. I was looking forward to using it but the sample did not stand the rigours of a backward roll from the boat and now resides I know not where.
It costs $30 but I don't expect to see anyone trying to sell it in the UK. Only in America!

PLUS	MINUS
+ A good joke	- Others might think you were being silly

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Appeared in DIVER - March 2000

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