The Javelin has no restrictions on construction materials, so a look at the various materials available is worth while. Plywood has been by far the most popular building material producing hulls that last many years when looked after. A good example of a Javelin built from plywood is Blunderbus built in 1983 and finishing 2nd in both this years Nationals and Sanders Cup. The next most popular material is foam sandwich with this years National and Sanders Cup winner Freckle Deckle being a good example. Each of these materials has their inherent advantages and disadvantages.
Plywood is cheap and produces a robust hull that is easily repaired.
A reasonable skill level is required to produce a light and strong ply hull. Foam sandwich produces a light and stiff hull that can be produced quickly, and easily once a mould is built. Foam hulls can be dented easily and repairs can add significant weight. Strip plank boats are very strong and robust but are very labour intensive to produce. With the intention of producing a number of hulls foam sandwich is the most suitable building material.