I have seen them used and they are effective, very difficult to use, I've tried and failed but those who know how make it look easy. I assume they are legal, better check it out! There is a booklet for recreational fishermen that list all the netting rules, mesh sizes etc.

Thanks for the info, as far as learning to throw, the best is to follow the basic principles ie get the net to rotate (anti clockwise for right handed and clockwise for leftys ) this centrifugal action causes the net to "spread". Apart from that rule, find what is a comfortable action and if you think you are coming right dont listen to anyone who says you are doing it wrong. Also when hunting the bait, it is better to keep a low profile, be dead quiet and let them come to you. Good luck coolbest.