Lift Bags for Fossil Hunting

[rfwoodvt]

Just musing a concept about getting significant amounts of weight from fossils back to the surface while minimizing the effects to my buoyancy.

I'm sure lift bags would work, but how small are they available? Don't see where I'd need to recover more than 20# per dive. In addition to the classic lift to the surface I was also wondering there might be a way to have it more neutral and alongside me as I hunt and later ascend.

Welcome your thoughts!

 

[rx7diver]

Just musing a concept about getting significant amounts of weight from fossils back to the surface while minimizing the effects to my buoyancy.

I'm sure lift bags would work, but how small are they available? Don't see where I'd need to recover more than 20# per dive. In addition to the classic lift to the surface I was also wondering there might be a way to have it more neutral and alongside me as I hunt and later ascend.

Welcome your thoughts!

You might take a look at Carter Lift Bags.

rx7diver

 

[johndiver999]

Just look at an smb, with an over pressure relief valve. Should not be too hard to manage, as long as you keep the rig somewhat negative during the dive. It might be nice to be able to release it to float unattended to surface and be recoverable by the boat. Alternatively, maybe have a reel attached and when you begin final ascent, let it float up and spool out line and you reel yourself back up to it?
If you want I may have a used 25 lb cater lift bay in the garage, but to be honest, I think a sealed smb would be better than an open bottom bag like I have. I would sell
It for cheap.

 

[Fishhy]

I know calabash digger uses a 60# wing- he had mentioned some restrictions on what you are allowed to use a lift bag for when he's digging for artifacts. So I recommend double checking regulations as well.

 

[rfwoodvt]

I know calabash digger uses a 60# wing- he had mentioned some restrictions on what you are allowed to use a lift bag for when he's digging for artifacts. So I recommend double checking regulations as well.

No restrictions on taking fossils where we dive but it isn't the number that adds up to the weight. A couple of Dugong ribs and a whale vertebra or mammoth tooth will get ya over 20# in a heartbeat.

Part of the reason I'm chewing on the idea is that I don't want to rely on my BC for helping with the heavier loads. Sorta playing, what-if I have a too small BC, what-if my BC fails, and so on. I also don't want to play yo-yo unnecessarily back and forth to the boat/float.

Also doing it as an academic exercise, a bit of mental floss.

 

[Fishhy]

No restrictions on taking fossils where we dive but it isn't the number that adds up to the weight. A couple of Dugong ribs and a whale vertebra or mammoth tooth will get ya over 20# in a heartbeat.

Part of the reason I'm chewing on the idea is that I don't want to rely on my BC for helping with the heavier loads. Sorta playing, what-if I have a too small BC, what-if my BC fails, and so on. I also don't want to play yo-yo unnecessarily back and forth to the boat/float.

Also doing it as an academic exercise, a bit of mental floss.

For sure, if it's allowed, you should use a bag. You could have an uncontrolled accent if you accidently dropped something that big and are using your BC to help you lift. Just wanted to point out there might be restrictions.

 

[rongoodman]

Just look at an smb, with an over pressure relief valve. Should not be too hard to manage, as long as you keep the rig somewhat negative during the dive.T

The problem with an SMB is that the dump valve is on the bottom and the air will be in the top, so you won't be able to adjust its lift. Lift bags have the OPV on the top, where the air is.

 

[rx7diver]

Just musing a concept about getting significant amounts of weight from fossils back to the surface while minimizing the effects to my buoyancy.

I'm sure lift bags would work, but how small are they available? Don't see where I'd need to recover more than 20# per dive. In addition to the classic lift to the surface I was also wondering there might be a way to have it more neutral and alongside me as I hunt and later ascend.

Welcome your thoughts!

Another thing you might think about. You probably want a lift bag that's rated for a load a bit heavier than what you are expecting to be lifting. A bag's lift capacity is determined when the bag is completely filled. You might not be able to get the lift bag completely filled.

rx7diver

 

[Celt]

No restrictions on taking fossils where we dive but it isn't the number that adds up to the weight. A couple of Dugong ribs and a whale vertebra or mammoth tooth will get ya over 20# in a heartbeat.

Part of the reason I'm chewing on the idea is that I don't want to rely on my BC for helping with the heavier loads. Sorta playing, what-if I have a too small BC, what-if my BC fails, and so on. I also don't want to play yo-yo unnecessarily back and forth to the boat/float.

Also doing it as an academic exercise, a bit of mental floss.

Get a 25kg lift bag with dump, don’t use your bc, apart from the squeeze of over inflation if you drop something you won’t dump fast enough. You can bring the bag along with you and add a little air as you collect items . Bring it up with you and clip it to your real then leave it off to the surface and sit on it for your stops.

 

[johndiver999]

The problem with an SMB is that the dump valve is on the bottom and the air will be in the top, so you won't be able to adjust its lift. Lift bags have the OPV on the top, where the air is.

Well, I personally have never done this, so it is what I envision. You start filling the catch bag with heavy stuff. When it gets too heavy to move around easily, you put a little air in the smb and keep it negative so it stays put.

At the end of the dive, you just send it up without trying to control it... Seems easiest thing to me.

I have used a dive gear express cheap lift bag with 65 lbs of lift and it works well for anchor recovery and it is not too big to carry.

DGX Gears Lift Bag { 65 lb | 30 kg }

DGX { 65 lb | 30 kg } Lift Bag in high visibility Orange has a semi-closed bottom.

www.divegearexpress.com