Review Diving the Avelo System

[Germie]

The scary bit would be if you jumped in, had some issue (rescue somone else, freeflow, fell in, whatever?) then need surface buoyancy fast. With an air filled BCD that is no problem as it takes a couple of seconds.
The Avelo has to displace water against 300 bar = 300kg/cm = 4300psi which takes a long time - 30+ seconds to a minute.

In the case of a rescue scenario -- sh!t does happen -- you need lots of surface buoyancy to hold up two people.


Avelo is a trim buoyancy device and should be dived with some form of additional buoyancy, such as a life jacket or BCD.

Exactly.
But now it is waiting till someone writes: 'Do a course, then you will get the answer, you don't know what you don't know'.

 

[inquis]

The scary bit would be if you jumped in, had some issue (rescue somone else, freeflow, fell in, whatever?) then need surface buoyancy fast. With an air filled BCD that is no problem as it takes a couple of seconds.
The Avelo has to displace water against 300 bar = 300kg/cm = 4300psi which takes a long time - 30+ seconds to a minute.

I think you have this backwards. Increasing lift is quick, as the 200-300 bar is pushing the ballast water out. Your point about limited buoyancy in an emergency still stands: you're supposed to top out at a mere +1 kg (+2 lb).

Related to negative entries, I'm not sure how one becomes negative while on the boat. People already get upset when you put a mask in the camera bucket. Can you imagine the horror??

 

[Wibble]

I think you have this backwards. Increasing lift is quick, as the 200-300 bar is pushing the ballast water out. Your point about limited buoyancy in an emergency still stands: you're supposed to top out at +1 kg (+2 lb).

Related to negative entries, I'm not sure how one becomes negative while on the boat. People already get upset when you put a mask in the camera bucket. Can you imagine the horror??

Thanks for pointing this out. Have removed my comment

 

[EdMcNeill09]

About the weight mentioned in the tables above. I am sadly a very bouyant person. This means with a 10 liter steel tank, ali backplate+wing, and a drysuit I need about 12kg of weight. If I dive the avelo, this will not be zero. You must be able to get under. Probably it will be 3kg less as I can reduce the amount of weight by taking a steel backplate (3mm steel, 3kg negative). But then you still need the weights, but it is not on a weightbelt. A 300 bar tank is a little bit heavier than a 232 bar steel tank. So this can reduce some weight too, but not that much. At surface the difference is 1-1.5 kg depending on which tank you take. The system itself maybe is also a little bit negative, so that reduces again some weight. But it is impossible to go from 12kg to max 3.

When I dive a Scuabpro Hydros and an aluminum 80 I need 14 lbs with my well worn 5mm suit. When I dive my Steel XDeep Zen I need an additional 8lbs. When I dive Avelo my weight calculation says I need 6lbs but I'm a bit dense so I actually need no weight. I weight 225lbs on a good day. Because I know what I need I can boost my Avelo tank to 3700psi instead of 3100psi and can descend without adding any water to the tank. This gives me about the same amount of gas as an aluminum 80. Because I'm just a little negative when I enter the water I do need to fin a little bit to stay on the surface while my divers enter the water. Very easy to do.

I don't know what you would actually need in terms of weight but expect it is less than you think.

 

[EdMcNeill09]

Related to negative entries, I'm not sure how one becomes negative while on the boat. People already get upset when you put a mask in the camera bucket. Can you imagine the horror??

Negative entries are super easy. Because we enter the water with swimmers buoyancy it is easy to swim down. I do this a lot when I attach the dive boat to a mooring. I simply giant stride in turn down and start finning. Easy. It's even easier if I'm diving a boosted tanks with an extra 2lbs of gas. In such a case I enter the water about 1lb negative. I don't do this often but I do regularly dive with a couple of customers on aluminum 80s that are as good or better on gas consumption than I am.

 

[EdMcNeill09]

BTW I doubt the Avelo will be CE certified as there's insufficient buoyancy available. Why do wings/BCDs have so much buoyancy? (to keep the diver afloat with their face clear of the water)

The Hydrotank was certified to DOT as a DOT UN/ISO pressure vessel CA2019120503. The DOT UN/ISO designation means that the Hydrotank took no exceptions to the ISO 11119-2 design specification.

It should be known that a DOT-SP means the manufacturer or designer of the pressure vessel took an exemption to something in a design standard. A DOT-SP pressure vessel indicates that something in the pressure vessel was not completed to 100% of the design specification.

The Hydrotank was also certified to PED for use where the CE mark is valid. The Module was CE PED Module B. USA-21/06/289/001

 

[EdMcNeill09]

Another approach would be to apply a large percentage of the training cost (say, everything beyond the cost of a 2-tank dive on the same boat) to the purchase of an Avelo.

Good idea. I'll pass this along to the Company.

 

[Germie]

Negative entries are super easy. Because we enter the water with swimmers buoyancy it is easy to swim down. I do this a lot when I attach the dive boat to a mooring. I simply giant stride in turn down and start finning. Easy. It's even easier if I'm diving a boosted tanks with an extra 2lbs of gas. In such a case I enter the water about 1lb negative. I don't do this often but I do regularly dive with a couple of customers on aluminum 80s that are as good or better on gas consumption than I am.

If I swim, I am very bouyant, to get under I have to swim very hard. So this does not work for everybody. In fresh water to do freediving I need 3kg of weight, in salt it is more.

When I dive and need to do a negative Entry, I don't fin down, I just let me go down. This does not cost any strength. To swim down as you write (a giant stride and then start finning) means you cannot go down without doing nothing.

To start a diving knowing you are a little bit negative with a boosted tank (and no option to put air somewhere you can float), this doesn't sound very safe to me. What if your buddy loses consciousness and you need to hold him or her at the surface, he or she will also be a little bit negative.
If there are waves, I am always happy I can make myself floating at surface till we go down. I do not like struggling in currents and waves. At surface I want to be relaxed.
Also sometimes we dive here in such currents that we need some extra weights to get down. So this means your bcd must be ableto handle this extra weights. We have to pull us down on a rope. This is way much harder if you don't take the 1-2kg extra of weights.

So for now I still don't see advantages that are solved with the Avelo. I only see more limits than with a normal bcd or bp+wing system.

 

[Joneill]

Negative entries are super easy. Because we enter the water with swimmers buoyancy it is easy to swim down. I do this a lot when I attach the dive boat to a mooring. I simply giant stride in turn down and start finning. Easy. It's even easier if I'm diving a boosted tanks with an extra 2lbs of gas. In such a case I enter the water about 1lb negative. I don't do this often but I do regularly dive with a couple of customers on aluminum 80s that are as good or better on gas consumption than I am.

Not quite that easy - I have issues with clearing my left ear if descending head down so I prefer to drop feet first and flair as I clear my ears. This is one of many reasons why I have no interest in this system - it's a more limiting solution for a problem that I just don't have.

 

[inquis]

Negative entries are super easy. Because we enter the water with swimmers buoyancy it is easy to swim down.

We seem to have very different ideas of what a "negative entry" entails, particularly the speed of descent and lack of exertion. (It may be called a "hot drop" in your area?) The point is to maximize both the odds of finding the object of interest and the gas you'll have to see it.