ahh a subject that really turns my wheels - fishing for snapper and big ones at that. All of what I am about to say is applied to NZ snapper but the species is the same and local location does make a small amount of difference.
First and foremost, I am always absolutely amazed at the size of bait a snapper can take. I have straylined 4 pilchards (15cm's ones baitcottoned together) for only to be sucked down by a 45cm snapper without a blink.
As pointed out by squiddy, snappers are moochers but the second biggest tip I can give you is snappers love fresh bait, caught in the region they are in. Examples are, snapper on the sand close to the beach love crabs, pippis, shelfish, small bait fish and other crustasions in the region. Snapper around reef structure love the bait fish, sea egg's, and other natural food.
Snapper at times are also very picky, certain times of the year (just before spawning) they require a certain ensyme that comes mainly from squid, thus squid can sometimes be the best of baits and sometimes the worst.
If you can't get fresh bait on location then my next alternativie is the pilchard. Experienting with commerical baits is underway here in NZ and funny enough its the oiler the better - the latest one for release has been half or whole small commerical salmon.
Here's my pick of baits - in order if I can get them
1) blue maomao (whole 15cm model given the Dr 90210 treatment with its back and bottom stripped back so its long and skinny, dripping with blood)
2) fresh bloody, skined kahwai fillet (aussie salmon) - the big snappers = whole fillet, 45cm snappers - half fillet - got smoked this year byt a big snapper 25lb+ on a half aussie salmon cut squarely down the middle lenghtways with the salmon being 30cm long
3) whole piper (also known as garfish) - break the beak off and strayline - often taken by kingfish due to the silver and lifelike looking
4) butterflied jack mackerl - cut the half fillet both sides of the mackerl from tail section forward and remove the tail and backbone leaving the head section and 2 fillets attached) - big snapper candy this one
5) a live squid - yeah baby these things rock if you get the right size at the right time of year
If I've got to use frozen bait then
1) pilchards - whole rigged as on a double strayline - I've a new way of rigging them that has been past on from "the master in yak fishing" - last year using this rig has caught 11 x 20lb+ snappers - no lies hear and to day he's caught 3x30lb+ snappers - yes the legendy one - I'm under promise not to let the word out and his jedi mind tricks are strong
2) skippy tuna, strip baits
3) squid, whole nz squid
4) squid, whole arrow squid
That is all for now - more later I may even take a few pictures of some baits and post them sometime to give you an view of what is used.
Did I mention I love fishing for snapper.....
