For me, two things have been successful with my oldest: take him out as much as i possibly can and FOOD. Yes food. let them eat all friggin day if they want. if they are fed they will go forever. Variety of snacks dont just bring cauliflower or you'll pay for it. I started with my oldest when he was 18 months old, he got his sea legs quickly. By the time he was 3 we did a 4 night trip to desolation sound, just him and me. When he was 4 (last summer) we soloed a 6 night trip in Clayoquot sound. Did the hike to the hot springs and everything. These are some of the best trips i can remember. No we don't come home with the boat loaded with fish, though we did hammer a 58lb halibut on our own on the Clayoquot trip
Honestly i reserve the "meat runs" for Renfew with other adults because young children dont do well going to swiftsure bank (dont ask me how i know). Adventures! They dont remember "that salmon", but that waterfall we went to explore in the dinghy, oh man he still talks about it. He barely fishes on the boat, he has his trucks and toys and keeps him busy. Everyone has their own style but i enforce a no tablet policy on the boat and i've been lucky that it has worked out so far. Oh and lastly, have fun and let them be part of the decision making! When we go prawning, i set half the traps and then i show him the chart, and he touches where he wants the traps. And you know what? most of the time he picks better spots than me LOL
The younger one is a different story though! but he'll get used to it eventually as well. Every kid is different. Don't give up!
One thing to add: Amount of trips per year you can do if you are leaving the kids at home with the wife and just going with your buddies: Very limited per year and costs a lot of credits
Amount of trips if you take kids along per year: Unlimited