Sacking Fish

Can someone explain the principle of putting fish in specialised sacks instead of keepnets?

As far as I can work out, at least in a keepnet the fish can swim about albeit only a limited amount. But in a sack it looks as if they are locked in one position and cannot even turn around.

Carp have a few serrated rays at the front of their dorsal that can get caught up in normal keepnet mesh, had it happen to me before I knew better, always cut the net if you have to use one.

You've also got the calming affects that dark sacks have over the fish. Next time you catch one, try covering its face and eyes with a wet sack/cloth, always has a calming affect. In addition, if the carp was thrashing up and down inside a keep-net then its going damage itself ad other fish within. (and in my opinion, the ew mesh nets out too). I once caught a match angler throwing a 12lb carp into a keepent on top of an already filled bag. As Roto was my witness, lets just say I wasn't too happy.

Us carp anglers have antiseptic creams, padded carp mats and comfy slings, but you can just call us sensitive...

Fish tend to constantly swim around inside keepnets, and can get serious fin damage. The all-enveloping soft sack doesn't allow this to happen, but watch out for gravel rash on carp, where they're sacked in too shallow water over a gravel bottom. Pike are OK-ish in sacks, but pike tubes (like thin keepnets made of carp sacking) are much better.