Lauan is a tropical hardwood used to make construction-grade plywood.
Some folks think that it's suitable for boatuilding.
To some degree, you get what you pay for. Over the last 10 years I've built at least 4 boats out of lauan plywood, in each case drawn to that material by a limited budget. Every time, I found myself fighting with voids in the core, and, just as serious, failures of the glue between the plywood veneers. What differs is the care with which the glue is applied between layers in manufacture and the quality of the wood being glued. Manufacturers of okoume, most of them in Europe, must meet various internationally recognized standards such as British Standard 1088, which prohibits voids or dry spots in the glue.