,now about the ducks.You mentioned getting busted on your approach,what time are you getting into your cove?Are you getting in well before legal time and setting up?If not I would recommend you do.Also,how well is you canoe covered up?This is important since ducks have great vision and can pick out colors or shine from a respectable distance.Same goes for clothing and gear.Eyeglasses can flare birds bigtime,shotgun barrels if they have a shiny blue job will do the same.A camo face net is a great help,keeps birds from seeing the "shine"from your skin.Could you hide the canoe in reeds and set up away from it?A smaller profile is harder for ducks to pick out,if you have to hunt out of the canoe then cover it the best you can.If you have a choice between enough camo cover and too much,go with too much.
You said you shoot a 2 3/4 " 12 gauge.What shot shells are you using?Shot size?If you stay with the 2 3/4 " then I suggest useing the fastest load you can buy in #4 shot.Winchester Drylock/expert are good.Improved cylinder choke and closest possible range will be very effective.
You have 4 beat up dekes,doesn't sound inviting and I doubt the birds will find them any different.Best thing to do is clean them up and paint them.If you don't think you can do a good job don't worry,just get some flat black spray paint,black decoys are just as effective as any other pattern.Walmart sells cans of flat black exterior latex for less than a buck a can.Works great.A dozen dekes is a good number for a pond or lake 2 dozen for bigger water.
Your 10 yr old step son,is he any good with that 20 gauge?Steel shot in a 20 requires a very competent shooter or you're going to shoot holes in the sky or worse,cripple birds.Even bismith in a small gauge needs a good shot shouldering the gun.If he is good then I would suggest using Bismith not steel.Also you should be in charge of the shooting situation.Make sure he shoots only when you are sure he has a good shot.
Calls,start with a double reed,they are more forgiving than single reeds.Practice a whole lot.When birds are coming in,shut up and let them.Know when and when not to call.Most calls have instuctional tapes with them you can use to practice with.One final suggestion, when you can't retrieve the downed bird include it in your bag anyway.While this isn't the law it makes for a good conservation practice and you won't make enemies of other waterfowlers.Eventually you will most likely want a dog.Thats another matter for a different day.
My lab is still the best hunting partner there is.