I spent from April 3rd and 18th, 2009 on a beach near LA constructing a concrete boat. The form used to make the boat and the hull itself were made of beach sand.

The boat was launched April 19 at the Marina Del Rey Municipal Boat Launch

The process used to produce a concrete boat using beach sand as both a form and a material is described in the 1971 edition of the The Whole Earth Catalog.