Some problems, looking for solutions?

[lord1234]

Riddle me this: A diver is constantly at about 20* trim and finds his knees are the problem(down) and he keeps pointing his fin tips downwards(towards the ground).

How would you adjust that divers gear to fix the problem?

This same diver also complains of "not being able to see in front of him, even when he puts his head as far back as he can". He can barely see out of the top of his mask. He is definitely not angled "down" but straight or in this 20* position.

The diver is weighted properly.

 

[LiteHedded]

Riddle me this: A diver is constantly at about 20* trim and finds his knees are the problem(down) and he keeps pointing his fin tips downwards(towards the ground).

How would you adjust that divers gear to fix the problem?

This same diver also complains of "not being able to see in front of him, even when he puts his head as far back as he can". He can barely see out of the top of his mask. He is definitely not angled "down" but straight or in this 20* position.

The diver is weighted properly.

my guess without seeing him is his tanks are too high on his back. compensating for that with feet down. he's probably not motionless either.

 

[lord1234]

Would tanks being dropped lower not move the center of gravity FURTHER down, thus causing the diver to be heavier towards their butt, thus causing more knee drop?

 

[ucfdiver]

Your image doesn't work, but my gut tells me:

1) Tank/weight isn't high enough, shoulder straps too tight or crotch strap too lose.
2) Wing isn't shaped properly.

The diver needs a low profile mask if that's blocking his view.

Would tanks being dropped lower not move the center of gravity FURTHER down, thus causing the diver to be heavier towards their butt, thus causing more knee drop?

I think Brian is saying that he's angling himself down to avoid the weight "turtling" him. Without video of the diver *trying* to stay 100% motionless it's really hard to say.

No matter what, it's safe to say that he is NOT weighted properly. He might have the right quantity of weight, but it's located incorrectly.

 

[LiteHedded]

Would tanks being dropped lower not move the center of gravity FURTHER down, thus causing the diver to be heavier towards their butt, thus causing more knee drop?

yea. if my hypothesis is incorrect.
but if he's head heavy and compensating for it with his flippers and putting his legs down, this will fix it

tell diver to stop moving, then watch him. you should see the problem then

 

[lord1234]

mask type: Genesis LVX Two Window Mask at LeisurePro I'm pretty sure thats pretty low profile...

wing is a hog 40lb(or 45lb) doubles/donut wing(not horseshoe)

Tank's are actually pretty high in the bands with a gap of ~2 inches from the crown of the tank to the top band.

Tanks are AL80s

 

[LiteHedded]

tanks are too high. i think i win. I imagine his head is hitting the isolator or the hoses.
drop them in the bands. if that's not enough you can move them lower on his back with harness adjustments

 

[lord1234]

I'll make sure the diver tries that in their next dives...how far would you suggest moving the bands?

 

[LiteHedded]

bands should be at the crown

 

[TSandM]

When people move into doubles, it's quite common for them to be initially head-heavy, and the response is somewhat counterintuitive. The diver rears up to shorten the lever arm through which the weight up high has to work. I fought with my husband for months over this, telling him he needed to move weight DOWN on his body, and he did not believe me . . . but when he eventually did it, the trim fixed itself.

However, there is a second problem with the diver as diagrammed. Dropping the knees by flexing the hip joint, as shown, will tend to drop the entire leg. So this diver needs to think about keeping a straighter line from the shoulders to the knees. This is done using the gluteal muscles; it is very important that the diver NOT do it by arching the back, as this will cause pain over time.

With regards to the problem of not being able to see in front of him (or I wouldn't be surprised to learn this is a "her" instead), take a look at how the regulators are sitting behind the diver's head. Especially if the tanks are high, and if the regs are the type with an LP port at the bottom, the first stages, arranged as people normally do them with that type, may be preventing the diver from putting her head back, forcing her to look down. I fought with this for a long time, and even conferred with Natalie Gibb, who is even smaller than I am . . . she told me she tilts her head sideways in order to look forward. It works, but it's not very pleasant to do. My eventual solution was to angle one of the first stages to the OUTSIDE instead of inward, and I discussed this arrangement with JP Bresser to see if he could come up with any reason why it wasn't optimal, and he thought it was fine.