Rational for Elipse wing shape

[SangP]

Hi,

I have seen a lot of wings that are bigger at the bottom and not the top so I'm curious why the Halcyon eclipse wing is larger on the top.

Thanks

 

[Pullmyfinger]

I own one, so I'll take a shot at it.

Using a nearly empty tank (say 40 or 50 Bar), the common aluminum 80 is going to become more buoyant at the bottom of the tank.

Watch how an aluminum 80 floats in the water by itself....valve heavy...butt light.

When you add the weight of the 1st stage to it, then it would be the upper part of the tank that would need the additional flotation and not the bottom.

The Eclipse wing is only slightly larger at the top, so I don't believe it's having that big of an effect.

I'll wait for the official answer and see how close I got.

Take care,
Mitch

 

[eelnoraa]

I also have a 30lb eclipse, and I have a 40lb oxycheq to compare. let me take a shot at it too. The face that it is bigger on top really didn't do anything when diving. Assuming diver is properly weighted and in trim, the wing should take on the weight of the gas at most, so about 6-8lb at most, so the wing is almost empty, most if not all the air will be on the side of the wing, slightly wrap around the tank. So the bigger top is really only making difference when the wing is inflated to near full capacity, which only happen on surface.

I used to think Eclipse wing shape is wrong too, until I tried one, and I actually find it is easier to dive than oxycheq, mainly I can fell eclipse is easier to vent than oxycheq.

 

[SangP]

I also have a 30lb eclipse, and I have a 40lb oxycheq to compare. let me take a shot at it too. The face that it is bigger on top really didn't do anything when diving. Assuming diver is properly weighted and in trim, the wing should take on the weight of the gas at most, so about 6-8lb at most, so the wing is almost empty, most if not all the air will be on the side of the wing, slightly wrap around the tank. So the bigger top is really only making difference when the wing is inflated to near full capacity, which only happen on surface.

I used to think Eclipse wing shape is wrong too, until I tried one, and I actually find it is easier to dive than oxycheq, mainly I can fell eclipse is easier to vent than oxycheq.

I own one, so I'll take a shot at it.

Using a nearly empty tank (say 40 or 50 Bar), the common aluminum 80 is going to become more buoyant at the bottom of the tank.

Watch how an aluminum 80 floats in the water by itself....valve heavy...butt light.

When you add the weight of the 1st stage to it, then it would be the upper part of the tank that would need the additional flotation and not the bottom.

The Eclipse wing is only slightly larger at the top, so I don't believe it's having that big of an effect.

I'll wait for the official answer and see how close I got.

Take care,
Mitch

Thanks guys and I too would like to hear the official reason.

Here's my take on things. I'll make a few assumptions first.
1. The center of balance of my body would be the belly button in a frog kick position.
2. My lungs hold 0.5L of air during normal breathing conditions.
3. My entire body is neutral in water with the exception of the air in the lungs.

Weight around the upper torso Weight around legs
Regs 2kg Jet fins n straps 2kg underwater
Alu Plate 0.2kg (cus the plate sits on the back)
Lungs -0.5kg Tank at 50bar (-2kg)

Total Total
1.7kg 0kg

So the top of the wing is used to compensate for the heavy top?

The problem is in reality I'm a very feet heavy person if I don't have more air in the bottom of the wing, I'll end up standing straight in the water so a large head wing won't do it for me.

 

[DiverLaura]

They are slightly larger on the top to add buoyancy to the top of the system. With a single tank the air will stay in the top. A properly weighted diver will need this little extra at to offset the weight of the regulator and valve. Although if the diver has to much weight on his waist it won't help him trim out probably only make it worse. Additionally, it also helps with vertical surface flotation.

Thanks for the great question!

 

[Shftrdog]

I belive PullMyFinger is right

 

[eelnoraa]

.... Jet fins n straps 2kg underwater

Maybe time to switch to a pair of lighter fins for warm water diving. I am extremely leg heavy too. No chance I can be in trim in jet fins in wetsuit, warm or cold (thin or thick wetsuit). For warm water, I use a pair of OMS slipstream with spring strap. I am still abit leg heavy. I need to put 2-4lb on top camband. This is with Oxycheq Mach V 40lb wing, AL plate, canister light on waist harness, titanium 1st stage, AL80. Not sure if the weight (lack of) Ti 1st stage has anything to do with this.

Anyway, if you put 1.7kg (~3.5lb) of lift in a 30lb H wing, I doubt air will be in the top arc at all. It is not the highest part if diver is in trim

 

[divad]

Hi,

I have seen a lot of wings that are bigger at the bottom and not the top so I'm curious why the Halcyon eclipse wing is larger on the top.

Thanks

In my experience with an eclipsed-shaped wing and and a non-tapered wing, at the tipping point, the tapered wing was way more manageable in terms of trim. ( I like to think)

 

[SangP]

Hi Laura,

Yes, I agree in a perfect world where pp are balance right in the water the wing would be perfect, unfortunately for big foots and hobbits like myself, the more likely outcome would be flipping backwards and ending up standing straight in the water lol!

I also believe that anyone who is enjoys serious leg sports like cyclists, soccer players for example, their legs would be a lot heavier then other folks.

The weight of the reg pales in comparison to my legs in jets lol.

The other thing is due to the shape of the wings I am lower in the water then my oxycheq wing on the surface.

---------- Post Merged at 12:34 AM ---------- Previous Post was at 12:31 AM ----------

Maybe time to switch to a pair of lighter fins for warm water diving. I am extremely leg heavy too. No chance I can be in trim in jet fins in wetsuit, warm or cold (thin or thick wetsuit). For warm water, I use a pair of OMS slipstream with spring strap. I am still abit leg heavy. I need to put 2-4lb on top camband. This is with Oxycheq Mach V 40lb wing, AL plate, canister light on waist harness, titanium 1st stage, AL80. Not sure if the weight (lack of) Ti 1st stage has anything to do with this.

Anyway, if you put 1.7kg (~3.5lb) of lift in a 30lb H wing, I doubt air will be in the top arc at all. It is not the highest part if diver is in trim

I am trying lighter fins like the quattros but in comparison the feel is so different in a bad way. I added weight pockets to the cam band and it wasn't really right (too top heavy) now I have a pair at the shoulder straps and this seem to fit me better. I also am using oxycheq wings too.

 

[g1138]

I think the bottom is narrower to ease the dumping of air.
If the bottom was really wide, you'd have to tilt farther off your axis to dump all your air.

I don't think the shape really matters in terms of trim, if you are orientated head up, the air will all travel up; doesn't matter what the shape is unless were talking a large volume difference between the top and bottom of the wing. If the wing were really narrow then all the air would more likely be evenly distributed along your body (I'm talking an extreme 1ft width wing).

Wide wings at the tail end really do nothing to float your hips if the air isn't occupying that area in the first place. So I think the marketing plus behind such wings is actually a misconception statement. Even if you were at the deep depth where your wing would be filled more, it still wouldn't be filled enough to reach the entirety (assuming you're correctly weighted an at a horizontal-slightly head up DIR trim)