I agree, make your own. I used sumbrella for mine but a rip stop nylon can also be used for a lite waterproof boom tent.
When making mine i used grommets on the corners to attach with a bungee cord to form a tent for heavy rain. I also made pockets on each end to slide poles through to make it a canopy. The poles were made out of three foot sections of PVC that screwed together. Each had an eyelet on the end to attach shock cord. Works great for sun protection while allowing easy mobility. The whole thing collapses into a three foot long stowable unit.