Last summer I sat on the Ohio River dowtown and watched someone use one for about 45 minutes. I was surprised at the relative success. I would assume all game laws apply but he got a sirprising number of small fry.
got to be where i was decent at throwing a castnet when i lived in north carolina. they are legal to use for catching bait, but there are restrictions to both net and mesh size iirc.
some thoughts on castnets
1. you generally get what you pay for, but there is no reason to go overboard on price. if you get the higher end (i.e. calusa brand nets) they can get expensive
2. be sure of the bottom you are casting over. sand and small gravel are good, grass can be okay, large rocks and/or woody bottoms are no good. one snag on a stump or large rock and you could be out a net.
i will try to find the vid that i used as a guide.
this isn't the exact video i used, but it's close. however, instead of throwing the one bit over my shoulder, i held the edge in my teeth. look around, and you'll find a style that looks right to you, then practice repeatedly.
[ame]http://youtu.be/AGHb3U_YzJQ[/ame]
I keep one in a 3 gallon bucket with a lid on it so it is ready to go. Easy enough to learn how to use them. Best way is to have a guy who knows show you how and then practice from an elevated platform.
I learned off the back deck of a bait shop in Ocracoke.
I use one for the shad in Sullivan Lake. I'm not the best thrower but I can still get bait in the net...along with the occasional largemouth. To keep it legal the lm's go back in the water.
Here's the vid where I learned my throwing method.
[ame]http://www.youtube.com/watch?v=lOUkj2h2LjI[/ame]
I've owned a cheap one (from Wal-Mart if I remember right) for many years. Great for catching bait fish, but I haven't caught any sizable fish with it.
A great way to get bait. You can also use it for rough fish here in Indiana. Check regulations on size of net and mesh, though. Been throwing them since about 1960. A must have for any serious fishing in Florida. I catch shad for catfish here in IN.
Using a net to catch sport fish is illegal. There are some exceptions, however.
IC 14-22-9-1
Unlawful means of taking fish
Sec. 1. (a) Except as allowed by sections 3 and 11 of this chapter, a person may not take fish from waters containing state owned fish, waters of the state, or boundary waters of the state by the following:
(1) Means of:
(A) a weir;
(B) an electric current;
(C) dynamite or other explosive; (D) a net;
(E) a seine;
(F) a trap; or
(G) any other substance that has a tendency to stupefy or poison fish.
(2) Means of the following:
(A) A firearm.
(B) A crossbow.
(C) The hands alone.
(b) The methods or devices in this section may be possessed and used:
(1) under special permit issued by the director under rules that the director provides; or
(2) as otherwise provided by law.