Hi Tassie Boy
Blaze is spot on about bait, my two boys (3 and 7) love digging up pippies, helping take hardiheads out of a cast net, carefully picking up yabbies and small shrimp and other odds and sods we collect.
I think the secret is to mix things up for them and not do one thing for a long time. Even exciting stuff only holds their attention for about an hour then they just drift off.
Collect a few baits then put it on a rod in a holder while you go back and grab a few more, with luck the rod might get a run while collecting the rest of the days bait.
When you have enough to fish with hold the rods for a while, fish for a half hour then put them back in a holder and build a sand castle with them, explore the rocks, throw a few small stones in the water, just mix it up.
One other thing I find keeps the interest higher is to make a game or competition out of things, and give a running commentry of what's happening. OOh you getting a bite, do you think you will catch this one? that's it keep the rod up, this one is trying to pull your arms off..... they love it
gets them excited, and you make a big deal about the capture or loss.
My boys love detail as well, tell them why they are doing something, if you throw over there thats where the big ones live, etc if we make the barb poke out of the bait it makes it easier to catch the fish. Probably don't remember too much of what you tell them but the interaction seems to enjoyed.
seems to work for me anyway