Besides camping trailers, there are many other possible plywood based projects. Since I enjoy kayaking, plywood based kayaks are a natural fit for me. A number of years back, I found the Duckworks Magazine web-site. It’s a great resource for small wooden boat building.
This one is called a Toto, it’s a Double Paddle Canoe that I purchased plans for on the Duckworks Magazine site.
The Toto is a 13’ long and built using a stitch & glue method from two sheets of plywood. A person can build this type of kayak in a few weekends with basic woodworking and epoxy skills. It’s more of a calm water kayak, that has good stability and with moderate paddling effort can get up to 4 1/2 mph. The open cockpit design is great for fishing, bringing a furry friend and being able to stretch your legs out. Here is some pictures of my last one.