Rebreather World - View Single Post - Tech.s to clear up fishnets entangled on a Wreck

aquatiker · 30th July 2007, 07:33

Quote: (Originally Posted by maayanh)

I have done several dives to clear up fishnets, the techniques I've used are as following:

if the net was relatively new (less entangled, and only a few layers of net) then the technique was: to roll up the net (cutting and tearing where required) and every time it get to be 2 feet diameter , cut it off, tying it off and secure it on the side. after finishing all the area (or time) collecting the various rolls. and sending them to the surface vie lift bag. For a medium net this usually takes 60-90 minutes for 4 divers working simultaneously (more if the haven't done it before).

if the nets are old or in many layers than rolling up the net is almost impossible, and we usually only cut to expose entrances and exits and to remove specific peaces we find dangerous or interesting.

In every dive I've gone to remove netting (pieces more than 200 meters long) I've gotten at least a little entangled. therefor I use some variation of the rule of thirds when dealing with nets to make sure that even if I get entangled I still have time to get untangled. we go over all the equipment were taking and remove any thing non essential

(including buckles) tie off/tape up any straps. and make sure that every diver has at least two sharp cutting instruments. and while diving that each diver is seen by at least two other diver that can help them when (not if) they become entangled.

please note, I have not tried to use a lot of force to remove netting for fear of detestableising the wreck if that is not an issue that would defenaltly save time

Hi maayanh:

We have old and new pieces mixed all together; it will be quite a lot of work, for a few months!..
Anyway we got a pretty got number of divers split in 3 ind/team to work on specific spots.
Probably 4/team would be safer; 2 working, 2 monitoring in turns.

I also considered the idea of getting a regular vest,

but putted on top of the harness, and reversed; that is, all pockets turned inside, as was as buckles, etc. That way all instruments would not turn into edgy points and if one diver requires anything kept inside if, it´s just a matter of unzipping and zipping it again. If in a messy situation or with a lot of nets hanging out, that procedure should be done away from the wreck.

Another thing, would be to cover all units/tanks with a nice wrap with an elastic band on the end. (material: probably the same used in trucks to cover cargo).

These two ways would be a nice, safe and cheap way for us divers to keep it withing some safety margins.

Also thanks for reminding the thirds rule; i consider it as well, plus, i would like every team to have a bailout tank close (few meters) to the spot their working on, in case of necessity.

Still, i´m not yet convinced on what should be best...

Maybe partially as you said; new pieces rolled up and tied by small sections.

Older cutted of and kept on a mesh bag, or plastic bag to avoid getting stuck.

What about this?...

Rule to decide aging process on nets; (on pull, breaking off?..that can be somehow trickier, since their wrapped on each other..)

It´s going to be a hell of an operation!

(hell as in a lot of work, hopefully!!)

30th July 2007, 07:33	#7 (permalink)
aquatiker New Member Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Nov 2006 Location: Portugal Posts: 15	Re: Tech.s to clear up fishnets entangled on a Wreck or reef Quote: (Originally Posted by maayanh) I have done several dives to clear up fishnets, the techniques I've used are as following: if the net was relatively new (less entangled, and only a few layers of net) then the technique was: to roll up the net (cutting and tearing where required) and every time it get to be 2 feet diameter , cut it off, tying it off and secure it on the side. after finishing all the area (or time) collecting the various rolls. and sending them to the surface vie lift bag. For a medium net this usually takes 60-90 minutes for 4 divers working simultaneously (more if the haven't done it before). if the nets are old or in many layers than rolling up the net is almost impossible, and we usually only cut to expose entrances and exits and to remove specific peaces we find dangerous or interesting. In every dive I've gone to remove netting (pieces more than 200 meters long) I've gotten at least a little entangled. therefor I use some variation of the rule of thirds when dealing with nets to make sure that even if I get entangled I still have time to get untangled. we go over all the equipment were taking and remove any thing non essential (including buckles) tie off/tape up any straps. and make sure that every diver has at least two sharp cutting instruments. and while diving that each diver is seen by at least two other diver that can help them when (not if) they become entangled. please note, I have not tried to use a lot of force to remove netting for fear of detestableising the wreck if that is not an issue that would defenaltly save time Hi maayanh: We have old and new pieces mixed all together; it will be quite a lot of work, for a few months!.. Anyway we got a pretty got number of divers split in 3 ind/team to work on specific spots. Probably 4/team would be safer; 2 working, 2 monitoring in turns. I also considered the idea of getting a regular vest, but putted on top of the harness, and reversed; that is, all pockets turned inside, as was as buckles, etc. That way all instruments would not turn into edgy points and if one diver requires anything kept inside if, it´s just a matter of unzipping and zipping it again. If in a messy situation or with a lot of nets hanging out, that procedure should be done away from the wreck. Another thing, would be to cover all units/tanks with a nice wrap with an elastic band on the end. (material: probably the same used in trucks to cover cargo). These two ways would be a nice, safe and cheap way for us divers to keep it withing some safety margins. Also thanks for reminding the thirds rule; i consider it as well, plus, i would like every team to have a bailout tank close (few meters) to the spot their working on, in case of necessity. Still, i´m not yet convinced on what should be best... Maybe partially as you said; new pieces rolled up and tied by small sections. Older cutted of and kept on a mesh bag, or plastic bag to avoid getting stuck. What about this?... Rule to decide aging process on nets; (on pull, breaking off?..that can be somehow trickier, since their wrapped on each other..) It´s going to be a hell of an operation! (hell as in a lot of work, hopefully!!)
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