Think of it as "open carry WHILE fishing."
Don't play too much with going too or from. I haven't tried anything with it, but I wouldn't unless it was close to my house and I was walking there. There's no way for a police officer to prove or disprove that you're actually going fishing (except maybe if you have live bait to prove you're on the way to actually fish...)
Stick with CC until you arrive if you have a license/permit, or keep in a snapped/buckled holster in the car/truck under normal "securely enclosed" requirements until you arrive at fishing.
If you're going directly from your house to the pier/park (which is what you should do if you're trying OC for it), you would probably be well served with a normal OWB buckled holster the whole way there and back.
And no, don't stop at the gas station and grocery store on the way. Get your soda, chips, and bait ready before you're open carrying, or you're likely to get in trouble for pushing or abusing the law; most people and law enforcement won't take kindly to it if you're not going DIRECTLY to or from.