Your plans and patterns may include either the measurements or an actual full-size pattern for the deck and cabin top cambers. Using this pattern, it’s a simple matter to cut a hard pattern from plywood or suitable timber. If you get the balance right, you can cut a male and female pattern from one plank. The pattern will be used to obtain the correct camber when you’re bending the deck beams and cabin beams.

   On sailboats, the cabin and the pilothouse tops will usually have more camber than the decks.. On powerboats, the opposite is sometimes the case, although quite often the same camber is used throughout. If your plans don’t include full-size camber patterns, you can create patterns using the designer’s recommended cambers, as shown below. For instance, in a powerboat that will be fitted with a flybridge, it is best to have a minimum (but still some) of camber in the cabin or pilothouse top as this will form the sole of your flybridge and too much camber is not desirable.

Bulkheads

   If you’re building upright, you may have included some of the bulkheads as you were setting up the initial frames. It would also be possible to include bulkheads when you’re setting up an inverted hull, but it may involve raising the whole structure so far off the floor that it would be impractical. Any setting-up method that makes you climb or walk more than is absolutely necessary is not recommended. In cases where the hull is built upside down, my preference is to wait until the hull is plated and upright before considering the installation of any bulkheads. That gives you an overview of the hull, so you can take stock of the available space before making firm decisions about placing bulkheads that will affect the layout of the accommodation.

   You’ll need to decide which bulkheads will be metal and which will be plywood. The bulkheads that will be exposed to the elements should all be metal, including the aft bulkhead of the cabin and the bulkhead located at forward end of the aft cabin. If you have a pilothouse, the aft bulkhead should be metal. In Dutch powerboats, the aft end of the saloon or pilothouse is sometimes made partially of timber. This is acceptable if there is some awning or shelter over it to protect it from the elements. Bulkheads will usually be constructed from the same metal used for the decks. In boats under 40 feet (12.19 m), try to keep the number of metal bulkheads to a minimum, and use plywood where practical.