Lewis, "Chines" are the wood pieces that attach the sides to the bottom, they are made from a piece of wood maybe 3/4 x 1 inch (or bigger depending on baot size) and run from the stem to the stern. They are attached to the sides of the boat and give you something to nail,screw,glue the bottom to. 99.9% of modern home boat building is now done "stitch and glue" with this modern method a slurry of epoxy and silica is used to form a fillet at the joint and then it is reinforced with fibreglass. While this makes a strong watertight joint it is expensive, toxic and messy. When building a boat with a "curvy" hull wood chines need to be planned/cut to fit and this requires 3 brain cells and confidence hence the replacement with goop.
(Rant:At the end of the day the reality is the Epoxy industry has done a better job of marketing to hobby boat builders then the construction grade lumber industry. There is no profit for anyone in a wood chine (which uses 30 cents or a buck fifty of wood) but a stitch and glue chine puts signifigant dollars in someone's pocket)
When building a simple plywood boat IMHO there is no good reason to spend more on attaching the sides to the bottom then on the whole boat. The Hybrid boats and the Puddle Duck Racer hull mentioned above both are perfect candidates for wood chines (the free plans for the puddle duck racer show wood chines, but IIRC they are called "frames" and are attached to the sides of the boat.
Lewis if you think you are gonna build a cheap hull one thing you will want are some "bronze boat nails"- "Bronze Ring Nails" they are about 20 bucks a pound but worth every penny. They hold like nobodies bussiness, wont ruin a tool if you cut into one and make boat building a joy. Everything else you can buy at the local hardware store but you might need to order some bronze nails. Leevalley sells em but you can also order from the USA for the same price and mix/match sizes/length. The only trouble with them is that if you have extras you wont be able to help yourself and will build something with them LOL. No comaparable fastener exists.
Bill, you sure scored on that Lazer Hull that is the best thing you could hope for, If lewis could find a lazer or sunfish hull like that he would be set. I had a chance at a lazer hull once and I still regret missing the deal.