Tropical diving: correct amount of weight versus trim (correct weight distribution)

[lowwall]

I'd love to dive with Achim in the tropics and give him a shorty, cheap single strap BCD, crappy fins, an HP117 and film it. LOL. I'd be yelling at him "Eat some concrete! Harden the F up!" LOL

I'd bet on Achim. As he says in one of the comments on his video where he demonstrates technical kicks using Seawing Nova fins:

I wanted to make divers aware that it is not their gear which makes them perform good or bad but it is their skills and nothing else.

 

[Searcaigh]

So basically there is no good fin or bad fin, just poor application of whatever fin you use!

This will be good news for everyone using split fins knowing that the fins will not be a contributory factor to their eventual death.

 

[MichaelMc]

I wanted to make divers aware that it is not their gear which makes them perform good or bad but it is their skills and nothing else.

So if we took a car enthusiist and gave them springs but no dampening, loose steering, flaky throttle, all the weight on the right front, and seat and steering wheel canted 30 degrees toward the center of the car, then they would do just as well on fun winding roads or traffic?

We should tell the people that work hard to create responsive and ergonomic cars that they are wasting their time. None of their effort to provide a good environment for the driver matters.

Yes, skill and comfort matter, but there is no reason to stack the deck against yourself, if you have a choice. And doing better here is not hard.

 

[inquis]

You can clearly feel it, even on a single AL80.

Why would seahorse trim fix itself on the dive? That one is not really a trim issue.

I'm having difficulty following you. How is seahorse trim not a trim issue? You said that breathing the gas will impart a "trim shift of several kg", which if true would improve seahorse trim.

Considering only the mass of the gas is missing half of what's going on.

 

[berndo]

So if we took a car enthusiist and gave them springs but no dampening, loose steering, flaky throttle, all the weight on the right front, and seat and steering wheel canted 30 degrees toward the center of the car, then they would do just as well on fun winding roads or traffic?

We should tell the people that work hard to create responsive and ergonomic cars that they are wasting their time. None of their effort to provide a good environment for the driver matters.

A car is a pretty sophisticated machine. Dive gear is pretty basic. Even in a car, a better driver in a bad car is still the better driver. Crappy driver is still a crappy driver in a good car.

I'm having difficulty following you. How is seahorse trim not a trim issue? You said that breathing the gas will impart a "trim shift of several kg", which if true would improve seahorse trim.

Considering only the mass of the gas is missing half of what's going on.

No, I said the trim shift of the gear does not impact the diver. The large tanks going from butt heavy to butt light don't cause cave divers out of trim.

I said people diving like seahorses is because most if not many of them use way too much weight. Just an example: I just dove with a guy at some quarry that looked pretty bad. Full on seahorse. 150 dives or so. He had lots of air in his drysuit around the shoulders. We took 8 lbs off him before the second dive and his trim was way better on the second dive. Not great but way better. Couple more dives and he could be doing great.

Next trip you're on. Look at the bad divers and pay attention to how full their BCs are at depth and on stop depth. I'm telling you, you're going to see a lot of pretty full BCs.

 

[inquis]

Look at the bad divers and pay attention to how full their BCs are at depth and on stop depth. I'm telling you, you're going to see a lot of pretty full BCs.

Totally agree overweighting and poor trim usually go hand in hand.

 

[FishWatcher747]

I think some of us agree that the warm water rental gear of a jacket BCD with one tank strap and all the weight in a weight belt or weight in releasable pockets near the waist creates a foot heavy weight distribution. It creates seahorses.

Now when these people get to the point of wanting to get their own gear, what do they do? Since this is all they know they buy similar stuff as the rental stuff. Thus they stay being seahorses.

Now if one knew this is a problem one could bring trim pockets to put on the cylinder strap. That would help but would not be sufficient for my leg heavy long inseam body. I need the trim pockets on the upper cam band to get the proper weight distribution. But hey, there is no upper cam band.

The other problem with a jacket BCD is the air bladder cannot be moved relative to the harness. In a BPW one can move the wing down towards the feet relative to the harness and plate. The wing has long slots for the cam bands so the upper cam band stays high on the plate but the wing can be placed low. Cam band trim weights stay high, wing can be placed low.

 

[berndo]

I think some of us agree that the warm water rental gear of a jacket BCD with one tank strap and all the weight in a weight belt or weight in releasable pockets near the waist creates a foot heavy weight distribution. It creates seahorses.

It really doesn't though. It's just factually not true. The youtube dude made a video to show it.

When you dive bp/w or a poodle jacket, the gas in the bladder is on your back in the same place eitherway. The gas is only distributed differently in a wing vs a poodle when you fill it way up, like you would in the surface... not when there is just a little gas for buoyancy in the bladder.

 

[inquis]

I said the trim shift of the gear does not impact the diver. The large tanks going from butt heavy to butt light don't cause cave divers out of trim.

I agree the diver is not impacted, but that is because the mass reduction is offset by the lift reduction. Butt heavy/light doesn't matter. If I move a couple kgs (vertically) from a waistbelt to a camband around the base of an AL80, my trim doesn't change, and yet the tank is butt heavy.

 

[FishWatcher747]

It really doesn't though. It's just factually not true. The youtube dude made a video to show it.

When you dive bp/w or a poodle jacket, the gas in the bladder is on your back in the same place eitherway. The gas is only distributed differently in a wing vs a poodle when you fill it way up, like you would in the surface... not when there is just a little gas for buoyancy in the bladder.

I'm confused. Are you saying the center of mass and center of buoyancy relationship doesn't relate to trim?